Abstract:
This end-piece is of the type including two filtering membranes and support portions for supporting the membranes and channelling the fluid through the membranes. According to one aspect of the invention, it includes a connection portion which is moulded over the support portions in order to fix them together and the support portions include an upper support portion, a lower support portion and an intermediate support portion which is arranged between the upper support portion and the lower support portion, a membrane is retained between the upper support portion and the intermediate support portion and a membrane is retained between the intermediate support portion and the lower support portion and the membranes are overmoulded by the connection portion.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a liquid dispensing end-piece, of the type comprising two filtering membranes and support portions for supporting the membranes and channelling the liquid through the membranes. 
     BACKGROUND OF THE INVENTION 
     The filtering membranes used in end-pieces of this type are fragile. This makes the production of such a liquid dispensing end-piece complex and costly, even more so when the end-piece comprises a plurality of membranes. 
     An object of the invention is to provide a liquid dispensing end-piece which has a plurality of filtering membranes and which is easy and economical to produce. 
     SUMMARY OF THE INVENTION 
     To this end, the invention proposes a liquid dispensing end-piece of the above-mentioned type, which comprises a connection portion which is moulded over the support portions in order to fix them together, and wherein the support portions comprise an upper support portion, a lower support portion, and an intermediate support portion which is arranged between the upper support portion and the lower support portion, and wherein a membrane is retained between the upper support portion and the intermediate support portion and a membrane is retained between the intermediate support portion and the lower support portion. 
     According to other embodiments, the liquid dispensing end-piece comprises one or more of the following features, taken in isolation or according to any technically possible combination: 
     the membranes are overmoulded by the connection portion; 
     the support portions and the membranes are superimposed in a longitudinal direction; 
     it comprises two separate fluid circulation passages which are defined by the support portions, each of the two membranes extending across a respective passage; 
     a said passage has two ends and opens at one end through the upper support portion and at one end through the lower support portion; 
     a said passage has two ends and opens at one end through the intermediate support portion and at the other end through the lower support portion; 
     it comprises a passage for circulation of air, the membrane extending across the air passage being hydrophobic, and a passage for circulation of liquid, the membrane extending across the liquid passage being hydrophilic; 
     the intermediate support portion is connected to both the lower support portion and the upper support portion by means of snap-fitting; 
     the connection portion surrounds the intermediate support portion; 
     the intermediate support portion comprises reinforcement ribs; 
     the end piece further comprises a fluid channelling pipe, and the reinforcement ribs comprise at least one set of radial ribs which extend across the fluid channelling pipe of the intermediate support portion; 
     the support portions have a stacking axis (A-A), and the connection portion is overmoulded by means of injection from several locations which are distributed about the stacking axis of the support portions; 
     the intermediate portion defines at least one hole for receiving a member for locking an injection mould of the connection portion, which member is intended to be inserted in the at least one hole in order to immobilise the intermediate portion during the injection of the connection portion; and 
     at least one of the at least one holes for receiving a locking member defined by the intermediate portion delimits a portion of a passage for circulation of fluid through the end-piece, which opens laterally via the hole. 
     The invention also relates to a liquid packaging and dispensing assembly comprising a receptacle which has a neck, and an end-piece as defined above, arranged on the neck. 
     The invention and the advantages thereof will be better understood from a reading of the following description, given purely by way of example and with reference to the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectioned view of a liquid packaging and dispensing assembly comprising a liquid dispensing end-piece in accordance with the invention; 
         FIGS. 2 and 3  are exploded perspective and sectioned views, respectively, of the liquid packaging and dispensing assembly of  FIG. 1 ; 
         FIGS. 4 and 5  are exploded and assembled sectioned views, respectively, of the end-piece alone; 
         FIGS. 6 and 7  are bottom and top views of an intermediate support portion of the end-piece; and 
         FIG. 8  is a sectioned view of the end-piece received in the mould; and 
         FIG. 9  is a sectioned view along IX-IX of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1 to 3  illustrate an assembly  2  for packaging and dispensing an ophthalmic liquid in the form of an aqueous solution. 
     The assembly  2  comprises a receptacle  4  which is intended to contain the ophthalmic liquid, a drop-counting end-piece  6 , a stopper  8  for closing the receptacle  4  and a tamper-evident belt or ring  10  which indicates the first opening of the assembly  2 . 
     In the example illustrated, the receptacle  4  is a plastics material bottle which contains the ophthalmic liquid which has not been illustrated in the Figures. The receptacle  4  has a hollow body  12  which is extended with an upper neck  14  which extends along a vertical longitudinal axis A-A. 
     In conventional manner, the walls of the body  12  can be resiliently deformed by means of pinching in order to bring about a reduction of the inner space of the body  12  and the discharge of the ophthalmic liquid through the neck  14 . 
     The neck  14  comprises an outer threaded portion  16  which complements an inner threaded portion  18  of the stopper  8  in order to screw the stopper  8  onto the neck  14 . 
     The tamper-evident ring  10  is initially connected to the stopper  8  by means of breakable tabs  20  and is intended to become separated from the stopper  8  when it is opened for the first time. 
     To this end, the tamper-evident ring  10  comprises studs (not illustrated) which protrude towards the inner side of the tamper-evident ring  10  and which are intended to co-operate with a toothed crown  22  ( FIG. 2 ) of the neck  14  in order to allow the tamper-evident ring  10  to rotate in the screwing direction of the stopper  8  in order to allow it to be positioned, and to prevent the tamper-evident ring  10  from rotating in the unscrewing direction of the stopper  8  in order to retain the tamper-evident ring  10  until the tabs  20  have been broken when the stopper  8  is opened for the first time. 
     The end-piece  6  is intended to be fitted in the neck  14  in order to allow the ophthalmic liquid to be dispensed drop by drop whilst filtering the ophthalmic liquid being discharged from the receptacle  12  and the air entering the receptacle  12 . 
     The end-piece  6  has two distinct and separate passages: a first liquid discharge passage  24  and a second air inlet passage  26  ( FIG. 1 ). 
     The end-piece  6  comprises a hydrophilic micro-filtering membrane  28  which is arranged across the first passage  24  and a hydrophobic micro-filtering membrane  30  which is arranged across the second passage  26 . 
     The hydrophilic membrane  28  has the function of filtering the liquid being discharged from the receptacle  12  and preventing the entry of air via the first passage  24 . The hydrophobic membrane  30  has the function of filtering the air which enters the receptacle  12  in order to prevent contamination of the liquid and preventing the liquid from being discharged via the second passage  26 . 
     As illustrated in  FIG. 3 , the end-piece  6  comprises support portions which comprise a lower portion  32 , an upper portion  34  and an intermediate portion  36  arranged between the support portions  32 ,  34 . 
     The end-piece  6  comprises a connection portion  38  which is overmoulded on the support portions  32 ,  34 ,  36  in order to fix them together. 
     The membranes  28 ,  30  are retained between the support portions  32 ,  34 ,  36  and the two passages  24 ,  26  are defined through the support portions  32 ,  34 ,  36  which serve to channel the liquid and the air through the membranes  28 ,  30 . 
     As illustrated in  FIG. 4 , the lower portion  32  is generally in the form of a cylindrical disc having an axis A-A and comprises an opening  42 , a cannula  44  which protrudes upwards, a fixing skirt  45  which protrudes downwards and which is intended to be fitted inside the neck  14 , and an annular upper rim  46  which protrudes upwards and which is provided with internal reliefs  48  which are distributed along the upper rim  46 . 
     The intermediate portion  36  is generally in the form of a cylindrical disc having an axis A-A and comprises a first conduit  50  and a second conduit  52  which extend through the intermediate portion  36 . The first conduit  50  is stepped and extends along the longitudinal axis, becoming wider in an upward direction. The second conduit  52  comprises an inlet channel  54  and a chamber  56 , the chamber  56  being open in a downward direction and the inlet channel  54  extending transversely between a lateral outer surface of the intermediate portion  36  and the chamber  56 . 
     The upper portion  34  is generally in the form of a cylindrical disc having an axis A-A and comprises an annular lower rim  58  which protrudes downwards and which delimits a downwardly open recess  60  which is provided with internal reliefs  61 , a liquid dispensing nozzle  62  which protrudes upwards, and an outlet channel  64  which extends inside the nozzle  62  between a base of the recess  60  and the upper end of the nozzle  62 . 
     The outlet channel  64  allows ophthalmic liquid to be dispensed drop by drop, with a calibrated drop size, when the body  12  is squeezed by the user between his fingers. To this end, it comprises in conventional manner a narrowed portion which is followed by a widened portion. 
     When the support portions  32 ,  34 ,  36  are superimposed along the axis A-A, the upper portion  34  and the lower portion  32  are retained with axial spacing from each other by the intermediate portion  36 . 
     Furthermore, on the one hand, the opening  42  is connected to the chamber  56  in order to define the second passage  26  which opens in a downward direction and via the opening  42  through the lower portion  32  and transversely via the inlet channel  54 , through the intermediate portion  36 , between the upper portion  34  and the lower portion  32 . 
     On the other hand, the cannula  44  is connected to the first conduit  50  which is connected to the recess  60 , in order to define the first passage  24 , which opens at one end, downwards and via the cannula  44 , through the lower portion  32  and, at the other end, upwards and via the outlet channel  44 , through the upper portion  34 . 
     The hydrophobic membrane  30  is arranged between the lower portion  32  and the intermediate portion  36 . The lower portion  32  and the intermediate portion  36  comprise annular supports  66 , between which the hydrophilic membrane  28  is clamped so that the hydrophobic membrane  30  extends across the second passage  26  and an edge region  31  of the hydrophobic membrane  30  protrudes outwards. 
     The hydrophilic membrane  28  is arranged between the upper portion  34  and the intermediate portion  36 . The upper portion  34  and the intermediate portion  36  comprise annular supports  68 , between which the hydrophilic membrane  28  is clamped so that the hydrophilic membrane  28  extends across the first passage  24  and an edge region  29  of the hydrophilic membrane  28  protrudes outwards. 
     The end-piece  6  comprises means for fixing by snap-fitting the lower portion  32  to the intermediate portion  36  and the intermediate portion  36  to the upper portion  34 . 
     In the example illustrated, the snap-fitting means comprise a first set of flexible members  70  which are provided on the intermediate portion  36  and which are intended to co-operate with the internal reliefs  61  of the lower rim  58 , and a second set of flexible members  72  which are provided on the intermediate portion  36  and which are intended to co-operate with the internal reliefs  48  of the upper rim  46 . 
     As illustrated in  FIGS. 6 and 7 , the flexible members  70  of the first set are inclined and extend radially outwards and upwards. Each flexible member  70  extends around the axis A-A over a limited angular portion. The flexible members  70  are distributed around the intermediate portion  36  and separated by spaces  74 . 
     When the intermediate portion  36  is moved closer to the upper portion  34 , the flexible members  70  of the first set engage by means of resilient return on the internal reliefs  61  and immobilise the intermediate portion  36  on the upper portion  34 . 
     The flexible members  72  of the second set are similar. They protrude radially outwards and downwards. Each flexible member  72  extends about the axis A-A over a limited angular portion. They are distributed around the intermediate portion  34  and are separated by spaces  76 . 
     When the intermediate portion  36  is moved closer to the lower portion  32 , the flexible members  72  of the second set engage by means of resilient return on the internal reliefs  48  and immobilise the intermediate portion  36  on the lower portion  32 . 
     As illustrated in  FIG. 5 , the connection portion  38  is overmoulded on the lower portion  32 , the upper portion  34  and the intermediate portion  36 . It serves to provide mechanical connection and sealing between the support portions  32 ,  34 ,  36 . 
     The connection portion  38  also serves to immobilise the membranes  28 ,  30 , with the edge regions  29 ,  31  of the membranes  28 ,  30  which extend outside the passages  24 ,  26  being overmoulded. 
     The connection portion  38  extends between the lower portion  32  and the upper portion  34 , engaging on the rims  46 ,  58 , in particular on the internal reliefs  48 ,  61  of these rims  46 ,  58 . 
     The connection portion  38  surrounds the intermediate portion  36 , forming a sleeve around it. It further provides coverage between the flexible members  70 ,  72 , thus providing effective fixing of the intermediate portion  36  and locks the flexible members  70 ,  72  so that the intermediate portion can no longer be separated from the lower portion  32  and the upper portion  34 . 
     According to the invention, a method for producing the end-piece  6  comprises an assembly step in which the lower portion  32 , the upper portion  34 , the intermediate portion  36  and the membranes  28 ,  30  are stacked and the snap-fitting means (flexible members  70 ,  72  and reliefs  48 ,  61 ) are engaged. 
     This allows the stacking to be maintained at least temporarily in an adequate manner. This stacking can be readily handled without damaging the membranes  28 ,  30  since they are held and protected by the lower portion  32 , the upper portion  34  and the intermediate portion  36 . 
     The method then comprises an injection step illustrated in  FIG. 8 , in which the stack is arranged in a mould  78  which comprises a lower die  80  which comprises a recess for receiving the lower portion  32  and an upper die  82  which comprises a recess for receiving the upper portion  34 , then the plastics material is injected under pressure in order to form the connection portion  38 . 
     During the injection step, in order to prevent the molten plastics material from flowing into the inlet channel  54 , an insert  84  in the form of a needle is engaged inside the inlet channel  54 . The insert  84  is, for example, movably and removably mounted (arrow F) on the lower die  80 . 
     The molten plastics material is injected between the lower portion  32  and the upper portion  34 , around the intermediate portion  36 . The plastics material flows through the spaces  74  and  76  ( FIGS. 6 and 7 ) between the flexible members  70  and  72  so that it engages on the internal reliefs  41  and  68  and surrounds the flexible members  70  and  72 . 
     Consequently, the connection portion  38  is moulded over the support portions  32 ,  34 ,  36  and the edge regions  29 ,  31  of the membranes  28 ,  30 , which ensures that they are retained relative to the support portions  32 ,  34 ,  36 . 
     The connection portion  38  also forms a sealing joint between the support portions  32 ,  34 ,  36  which define the passages  24 ,  26 . 
     In the example illustrated, the connection portion  38  extends in the space between the upper portion  34  and the lower portion  32 . The invention is not limited to this embodiment and, in a variant, the connection portion  38  extends outside this space and bypasses the edges of the upper portion  34  and lower portion  32  in order to cover their outer surfaces and further improve the fixing. 
     The intermediate portion  36  serves to maintain the spacing between the lower portion  32  for connection to the neck  14  and the upper portion  32  for dispensing ophthalmic liquid drop by drop. 
     During the injection step, the intermediate portion  36  is not supported by the dies  80 ,  82  of the mould  78 . 
     The pressure applied to the outer surface of the intermediate portion  36  is high and tends to crush the intermediate portion  36 . In order to prevent such crushing, and as illustrated in  FIGS. 6 and 7 , the intermediate portion  36  comprises a set of reinforcement ribs  86  which are arranged in a star-like manner on the upper face of the intermediate portion  36 , and a set of ribs  88  which are arranged in a star-like manner on the lower face of the intermediate portion  36 . The sets of reinforcement ribs allow the quantity of material used to produce the intermediate portion to be limited, whilst providing it with an adequate level of strength. 
     Preferably, in order to prevent lateral displacement of the intermediate portion  36  during the injection step, and as illustrated in  FIG. 9 , the plastics material is injected radially into the closed mould  78  from injection locations which are distributed circumferentially about the axis A-A of the end-piece  6 , preferably in a regular manner. For example, two diametrically opposed injection locations  90  are used ( FIG. 8 ). 
     Furthermore, optionally, the intermediate portion  36  is retained radially inside the mould  78  during the injection step. To this end, as illustrated in  FIGS. 8 and 9 , it is possible to use the insert  84  for closing the inlet channel  54  and another similar insert  92  which is, for example, diametrically opposed and which is engaged in a blind hole  94  ( FIG. 4 ) provided for this purpose in the intermediate portion  36 . 
     The invention is also used for assemblies for packaging and dispensing other medical liquids which are intended to be dispensed, in particular drop by drop, such as solutions for the nose or the ears.