Patent Publication Number: US-2009227986-A1

Title: Infusion and/or Withdrawal Fitting for Biomedical Fluid Circuits

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of co-pending International Application No. PCT/IT2004/000079 filed Feb. 23, 2004, which designates the United States. 
    
    
     TECHNICAL FIELD 
     The present invention relates to an infusion and/or withdrawal fitting for biomedical fluid circuits. 
     More specifically, the present invention relates to an infusion and/or withdrawal fitting for biomedical fluid circuits, of the type comprising a tubular conduit having a first end connectable to a biomedical fluid circuit, and a second end closed by a cap. 
     BACKGROUND 
     The cap normally comprises a plug movable between an open position and a closed position for opening and closing the second end respectively; and an elastically deformable collar fitted to the conduit and connected to the plug by a flexible element to keep the plug and collar connected to each other when the plug is in the open position. 
     Known infusion and/or withdrawal fittings of the type described above have several drawbacks, mainly due to assembly of the collar to the conduit being relatively complicated, by requiring elastic deformation of the collar by the user. 
     A further drawback of known infusion and/or withdrawal fittings of the type described above lies in the relative ease with which the collar works loose from the conduit. 
     SUMMARY 
     It is an object of the present invention to provide an infusion and/or withdrawal fitting for biomedical fluid circuits, designed to eliminate the aforementioned drawbacks. 
     According to the present invention, there is provided an infusion and/or withdrawal fitting for biomedical fluid circuits. The fitting comprising a tubular conduit having first and second ends, and a cap. The first end connectable to a biomedical fluid circuit. The cap is adapted for fitting onto said second end. The cap comprises a plug, a collar, and a connecting means. The plug is movable between an open position and a closed position for opening and closing the second end. The connecting means adapted for keeping the plug connected to the collar when the plug is in an open position. The cap comprises a weakened portion connecting the plug to the collar. And the conduit comprises means for breaking the weakened portion when fitting the cap to the second end for detachment of the plug from the collar and for retaining the collar on the conduit. 
     According to the present invention, there is provided a fitting for biomedical fluid circuits. The fitting comprises a tubular conduit having first and second ends, and a cap. The first end adapted for connection to a circuit. The cap is adapted to fit on the second end of the conduit. The cap comprises a plug movable between open and closed positions, a collar, and a flexible element interposed between the plug and the collar. The flexible element is adapted for keeping the plug connected to the collar. The cap also includes a weakened portion for connecting the plug to the collar. The conduit includes an annular flange projecting outwards from an outer surface of the conduit. The flange is adapted to break the weakened portion when fitting the cap to the second end, e.g., to detach the plug from the collar and for retaining the collar on the conduit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: 
         FIGS. 1 ,  2 , and  3  show longitudinal sections, with parts enlarged for clarity, of a preferred embodiment of the infusion and/or withdrawal fitting according to the present invention in different operating positions. 
     
    
    
     DETAILED DESCRIPTION 
     Number  1  in  FIG. 1  indicates as a whole an infusion and/or withdrawal fitting for biomedical fluid circuits (not shown). 
     Fitting  1  comprises a tubular conduit  2 , which has a given longitudinal axis  3 , is defined axially by two surfaces  4  substantially perpendicular to axis  3 , is defined internally by a substantially truncated-cone-shaped surface  5 , and in turn comprises a wide, substantially cylindrical top portion  6 , and a narrow, substantially truncated-cone-shaped bottom portion  7  connectable to a biomedical fluid circuit (not shown). 
     Portion  6  is closed by a cap  8  comprising a plug  9 , which has a given longitudinal axis  10 , is substantially cup-shaped, is defined internally by an annular end wall  11  substantially perpendicular to axis  10 , and by a substantially cylindrical lateral wall  12 , and is closed axially, at wall  11 , by a central shank  13 , which projects axially from wall  11 , is substantially in the form of a truncated-cone-shaped cup with the same taper as surface  5 , and has a concavity opposite the concavity of plug  9 . 
     Plug  9  also has an annular collar  14 , which is substantially coaxial with axis  10 , is defined internally by a lateral wall  15  comprising a cylindrical portion  16  coplanar with wall  12 , and a truncated-cone-shaped portion  17 , and is joined to plug  9  at a pre-cut weakened portion  18  defined by a number of teeth  19  substantially parallel to and equally spaced about axis  10 . 
     Portion  6  and plug  9  are connectable by means of a threaded coupling  20 , and with shank  13  engaging portion  6  ( FIG. 2 ). 
     As shown in  FIG. 2 , when screwing cap  8  to portion  6 , teeth  19  of weakened portion  18  are broken by a breaking device  21  comprising an annular flange  22  extending outwards from the outer surface of portion  6 . 
     Flange  22  tapers outwards and is defined by two facing, substantially truncated-cone-shaped surfaces  23  and  24 , which are connected to each other by a substantially cylindrical surface  25  coaxial with axis  3  and connected to surface  23 , and by an annular surface  26  located between surfaces  24  and  25  and perpendicular to surface  25 . 
     With reference to  FIGS. 2 and 3 , once teeth  19  are broken, flange  22  is located between plug  9  and collar  14  to retain collar  14  on conduit  2 , collar  14  is connected in rotary manner to conduit  2 , and plug  9  is movable between an open position and a closed position opening and closing portion  6  respectively. 
     In the open position opening portion  6 , plug  9  is kept joined to collar  14  by a flexible element  27  extending between plug  9  and collar  14  and formed in one piece with plug  9  and collar  14 .