Abstract:
A one-way valve for medical infusion lines includes a first tubular connector and a second tabular connector, which define, respectively, an upstream passage and a downstream passage, which are coaxial and set transversely between which is a diaphragm made of elastically deformable material co-operating in a fluid-tight way with an annular seat to keep the valve normally closed. A filter, integrated in the valve, is axially clamped and blocked between the first tubular connector and the diaphragm.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to one-way valves for medical lines, for example, infusion lines and the like, of the type comprising a body formed by a first tubular connector and a second tubular connector that define, respectively, an upstream passage and a downstream passage, which are coaxial and set transversely between which is a diaphragm made of elastically deformable material, which co-operates in a fluid-tight way with an annular valve seat to keep the one-way valve normally closed. A predetermined pressure of fluid in the upstream passage brings about a displacement or an elastic deformation of the diaphragm and consequent opening of the valve, i.e., opening of the communication between the upstream passage and the downstream passage. 
         [0002]    Valves of this sort are used, for example, as check valves, which are purposely designed to open when the pressure in the upstream passage exceeds a predetermined relatively modest threshold value, and then to reclose promptly so as to prevent, with the maximum degree of saftey, any reflux from the downstream passage to the upstream passage when the pressure in the latter drops again below the threshold value, or else in the case of an even minimal overpressure within the downstream passage. 
       PRIOR ART 
       [0003]    From the patent documents Nos. EP,1099457B1, EP-1093828B1 and 1946793A1, all of which are filed in the name of the present applicant, there are known one-way valves of the type specified above, in which the annular valve seat is defined by a wall with conical surface of the first tubular connector, diverging towards the second tubular connector, and the diaphragm is constituted by the bottom wall of a cup-shaped element, the outer peripheral edge of which is normally pressed in fluid-tight contact against the annular valve seat under an axial thrust exerted by the side wall of the cup-shaped element. In operation, when the pressure within the upstream passage reaches the aforesaid predetermined value, an axial displacement of the bottom wall of the cup-shaped element is produced in the direction of the second tubular connector, as a result of which the corresponding outer peripheral edge contracts radially, moving away from the annular valve seat with a high degree of promptness and immediacy of opening of the one-way valve. 
         [0004]    In applications on medical infusion lines, a filter is normally provided for filtering any possible impurities contained in the fluid that traverses the valve. Traditionally, the filter consists of an element separate from the valve, set along the line upstream of the first tubular connector, or else a filtering body inserted within the upstream passage defined by the aforesaid first tubular connector. 
         [0005]    Both of the solutions prove far from practical and to some extent complicate production of the medical line. 
         [0006]    From the document No. WO-2010/107597, a one-way valve is known of the type specified above, in which the filter is integrated within the body and consists of a permeable membrane set transversely and carried by a peripheral ring engaged with interference fit or snap-action fit on an internal annular flange of the body set upstream of the valve seat with respect to the direction of flow through the valve. 
         [0007]    The above fit does not ensure the necessary stability of retention of the filter, which can be easily disengaged from the flange of the body, with the consequent risk of opening paths of flow without any filtering. 
       SUMMARY OF THE INVENTION 
       [0008]    The object of the present invention is to overcome the above drawback, and this object is achieved thanks to the fact that the one-way valve is of the type defined in the pre-characterizing part of claim  1 , the peculiar characteristic of which lies in the fact that the annular element of the filtering membrane is axially clamped and blocked between the first and second tubular connectors. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention will now be described in detail with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which: 
           [0010]      FIG. 1  is a schematic view in axial section of a one-way valve according to a first embodiment of the invention; 
           [0011]      FIG. 2  is an exploded view of the valve of  FIG. 1 ; 
           [0012]      FIG. 3  is a view similar to that of  FIG. 1  which shows a second embodiment of the invention; 
           [0013]      FIG. 4  is a view similar to that of  FIG. 1  which shows a third embodiment of the invention; and 
           [0014]      FIG. 5  is an exploded view of the valve of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    With initial reference to  FIGS. 1 and 2 , the reference number  1  designates as a whole the body of a tubular connector for tube-to-tube connection of a medical line for infusion, transfusion, and the like. It should be noted that the connector could be prearranged, in a way in itself known, for luer-to-tube, or else tube-to-luer, or luer-to-luer connections, or other types of connection normally used in medical lines. 
         [0016]    The body of the connector  1  comprises, in a way generally in itself known, for example, from the already cited document No. EP-1946793A1, a first tubular connector  2  and a second tubular connector  3 , both of which are normally made of a suitable moulded thermoplastic material, axially joined together in a permanent way, with the modalities clarified in what follows. 
         [0017]    The first and second tubular connectors  2 ,  3  define, respectively, an upstream passage or inlet passage  4  and a downstream passage or outlet passage  5  which can be connected to respective sections of tubing of the medical line. 
         [0018]    Set between the upstream passage  4  and the downstream passage  5  is a one-way valve, the open/close element of which, set within a widened portion  9  of the tubular connector  3  coaxially with the latter, consists of a cup-shaped element  6 , which comprises a circular bottom wall  7  and a skirt or side wall  8  and is conveniently made of a single piece of soft elastomeric material, for example, silicone rubber. 
         [0019]    The free edge  8   a  of the skirt  8  rests on a radial array of transverse projections  10  formed at the base of the widened portion  9  and delimiting respective radial channels that communicate on one side with a restricted central passage  11 , which is in turn in communication with the downstream passage  5 , and on the other with peripheral axial passages  12  designed to be set in communication, in the condition of opening of the open/close element  6 , with the upstream passage  4 . Preferably, the resting surface between the free edge  8   a  of the skirt  8  and the sectors  10  is provided, according to what is envisaged in the already cited document No. EP-1946793A1, only in angular portions separated by portions that do not provide a rest. 
         [0020]    The edge of the open/close element  6  comprised between the bottom wall  7  and the skirt  8 , which is designated by  13 , constitutes the sealing element of the open/close element  6  which cooperates with an annular valve seat  14  with conical surface. In the condition of closing of the valve (represented in  FIG. 1 ), the skirt  8  is subjected to a predetermined axial elastic preload and presses the edge  13  in fluid-tight contact against the valve seat  14  so as to interrupt communication between the axial passages  12 , and hence the downstream passage  5 , and the upstream passage  4 . When an overpressure of higher degree than a pre-set threshold value is produced within the upstream passage  4 , the axial displacement of the bottom wall  7  of the open/close element  6  in the direction of the tubular connector  3  causes separation between the edge  13  and the valve seat  14 , setting the upstream passage  4  in communication with the downstream passage  5 . 
         [0021]    According to the peculiar characteristic of the invention, the connector  1  incorporates, in an integrated way, a filter set through the line of flow between the upstream passage  4  and the downstream passage  5 , which is axially blocked between the first tubular connector  2  and the second tubular connector  3 , upstream of the open/close element  6  of the valve with respect to the flow through the body  1  of the valve. 
         [0022]    In the embodiment represented in  FIGS. 1 and 2  the filter consists of a transverse membrane  15 , made of an appropriate permeable filtering material, the outer peripheral edge of which is fixed on a radially inner flange  17  of an annular element  18  set between the tubular connectors  2  and  3 . The surface of the flange  17  opposite to the filtering membrane  15  defines the annular valve seat  14 . 
         [0023]    On the side opposite to the flange  17  the membrane  15  frontally bears upon an annular projection  16  of the tubular connector  2 , projecting axially towards the tubular connector  3 . The annular element  18  has a peripheral flange  19  for front coupling to a radially outer flange  20  of the tubular connector  2 , and a stepped side wall  21  for coupling to a complementary stepped internal surface  22  of the widened portion  2  of the tubular connector  3 . Fixing between the flanges  19  and  20  on one side and the stepped walls  21  and  22  on the other can be obtained by ultrasound welding, gluing, or any other suitable system. 
         [0024]    The central part of the membrane filter  15  moreover rests against an inner axial annular projection  23  of the tubular connector  2  and faces a restricted terminal portion  24  of the inlet passage  4 . 
         [0025]    The variant of the valve connector according to the invention illustrated in  FIG. 3 , is generally similar to the embodiment described previously, and here only the differences will be described in detail, using the same reference numbers for parts that are identical or similar. 
         [0026]    In the above variant, the annular element of the filtering membrane  15 , designated by  25 , is axially blocked in an annular seat  26  formed between the annular flange  20  of the tubular connector  2  and a complementary annular flange  27  of the tubular connector  3 , which in this case are directly fixed to one another. The annular element  25  is conveniently welded inside the flange  27 , Which is in turn welded to the flange  20 . 
         [0027]    The filtering membrane  15  is, also in this case, inserted peripherally between the flange  17  of the annular element  25  and the annular projection  16  of the tubular connector  2  and the valve seat  14  for the open/close element  6  is also formed by the surface of the flange  17  of the annular element  25  opposite to the one on which the peripheral edge of the membrane  15  is fixed. 
         [0028]    In the variant represented in  FIGS. 4 and 5 , where likewise the same reference numbers are used to designate parts that are identical or similar to the ones already described with reference to the previous embodiments, the filter is formed by a body made of moulded plastic material  35  having a perforated wall  36  and made of a single piece with an intermediate annular element  37  axially blocked between the radially outer annular flange  20  of the first tubular connector  2  and the second tubular connector  3 . 
         [0029]    The perforated wall  36  is formed with a series of micro-slits  38  separated by intermediate septa  39 . Alternatively, the aforesaid perforated wall  36  could present a micro-grid conformation. 
         [0030]    In the case of the example illustrated, the perforated wall  36  has a generally conical shape converging towards the inlet passage  4  and faces a wall  40  having a complementary conical shape of the first tubular connector  2 . Its apex projects towards the restricted terminal portion  24  of the inlet passage  4 . 
         [0031]    Also in this case, the intermediate annular element  37  forms the annular valve seat  14  for the diaphragm  6  and has a peripheral flange  41  for front coupling with the radially outer annular flange  20  of the first tubular connector  2 . Its side wall is also formed with steps  42  for coupling to the stepped internal surface  22  of the second tubular connector  3 . 
         [0032]    It should be noted that the perforated wall  36  of the filter body  35  could present a surface geometrically different from the one illustrated; for example, it could be spherical. 
         [0033]    Of course, details of construction and the embodiments may vary widely with respect to what has been described and illustrated herein, without thereby departing from the scope of the present invention as defined in the ensuing claims.