Abstract:
A retractable needle device to be attached to the forward end of a syringe. The device has a forward end with a needle assembly that is urged into the body of the device so that when the syringe and device are to be discarded, the needle is located internally of the body of the device to inhibit needles stick injuries.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to retractable needle devices. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to syringes that when packaged contain a medication to be injected. The present invention also relates to syringes having a retractable needle, such as the syringes described in U.S. Pat. Nos. 5,000,736, 5,125,898, 6,015,438 and 6,179,812 as well as International Patent Publications WO91/10461, WO01/17594, WO00/18454, WO92/18186 and WO98/48869. 
         [0003]    The abovementioned syringes have a number of disadvantages including not providing a needle retraction mechanism for a syringe (prefilled) that is delivered and packaged containing a medication to be dispensed. 
       OBJECT OF THE INVENTION 
       [0004]    It is the object of the present invention to overcome or substantially ameliorate the above disadvantage. 
       SUMMARY OF THE INVENTION 
       [0005]    There is disclosed herein a retractable needle device including: 
         [0006]    a hollow elongated body having a forward end and a rear end, and a bore surrounding a chamber; 
         [0007]    a needle assembly releasably mounted at the forward end, the assembly including a needle mounting and a needle, the assembly being configured so as to be receivable within said chamber so as to be contained within said body, said needle being in liquid communication with said chamber; 
         [0008]    a resilient member operatively associated with said mounting to urge said assembly into said chamber; 
         [0009]    a release member in said chamber movable from a first position to a second position, the second position being spaced from the first position toward said forward end, said release member being operatively associated with said mounting to release said mounting for movement relative to said body when said release member moves to said second position; and wherein said release member is positioned relative to said rear end, when in said first position, to be engaged by a syringe delivering a liquid to said needle via said chamber, the syringe causing movement of said release member to said second position upon a desired quantity of liquid passing from the syringe and being delivered via said needle. 
         [0010]    Preferably, said rear end has a socket to engage a forward portion of the syringe, with said release member projecting into said socket rearwardly with respect to said body. 
         [0011]    Preferably, said device includes a catch releasably attaching the mounting to the body, with said release member engaging said catch in said second position to release the mounting. 
         [0012]    Preferably, said catch includes a resilient clip on said mounting, the clip being movable from an expanded configuration to a retracted configuration by engagement with said release member when said release member moves to said second position, said resilient clip when its in its expanded configuration retains said mounting at said forward end while in said contracted configuration releases said mounting. 
         [0013]    Preferably, said clip is a split ring. 
         [0014]    Preferably, said release member includes a base extending longitudinally of said chamber and having a rear part engaged by the syringe, and a clip engaging part at a forward part of the base, said clip engaging part engaging said clip to cause operation thereof to release said mounting, said clip engaging part being releasably attached to said forward part and released therefrom subsequent to said clip releasing said mounting so that said clip engaging part moves with said mounting. 
         [0015]    Preferably, said clip engaging part includes a plurality of fingers that engage said clip to cause contraction of the clip to release the mounting. 
         [0016]    Preferably, said clip engaging part is secured to said forward part by a further clip. 
         [0017]    Preferably, said further clip contracts from an expanded configuration to a retracted configuration to release the clip engaging part with respect to said base. 
         [0018]    Preferably, said release member projects rearwardly beyond said socket so as to project therefrom to be engaged by a piston of the syringe so that the piston moves the release member to the second positions. 
         [0019]    Preferably, said resilient member is compressed between said mounting and body to urge said mounting with said needle into said chamber. 
         [0020]    Preferably, said resilient member is a spring. 
         [0021]    Preferably, the resilient clip on said mounting is of a frusto-conical configuration providing a head, retaining said mounting at said forward end, and a tapering portion tapering from said head towards said rear end, said tapering portion being engaged by said release member to cause contraction of said head to release said mounting. 
         [0022]    Preferably, said release member includes a frusto-conical socket that engages said frusto-conical portion to cause contraction of said head. 
         [0023]    Preferably, said head and frusto-conical portion are slotted to provide for contraction of said head. 
         [0024]    Preferably, said mounting has a rear portion engaged with a forward portion of said release member to maintain the needle assembly at said forward end, the forward portion of said release member being operable to release the rear portion of said mounting to thereby release said mounting, when said release member is moved to the second position. 
         [0025]    Preferably, the release member is resiliently deformed to release the mounting. 
         [0026]    Preferably, the mounting is resiliently deformed to release the mounting. 
         [0027]    Preferably, the rear portion of said mounting is an annular flange, and the forward portion of said release member is an annular lip, with the lip and flange engaged to sealingly close said space when said release member is in the first position. 
         [0028]    Preferably, said release member surrounds a space, with said needle assembly received within said space when released with respect to said body. 
         [0029]    Preferably, said space is sealingly closed when said release member is at said first position. 
         [0030]    There is further disclosed herein, in combination a syringe and the above device, wherein said syringe has a hollow body containing a piston, the syringe body having a forward end engaged with said rear end, and wherein when the syringe piston is adjacent the syringe forward end the syringe piston is engaged with the release member to cause movement of the release member to said second position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 
           [0032]      FIG. 1  is a schematic side elevation of a syringe and a syringe device; 
           [0033]      FIG. 2  is a schematic sectioned side elevation of the retractable needle and device of  FIG. 1 ; 
           [0034]      FIGS. 3 to 6  are schematic sectioned side elevations of various operating phases of the syringe and device of  FIGS. 1 and 2 ; 
           [0035]      FIG. 7  is a schematic sectioned side elevation of the forward portion of the syringe device of  FIG. 1 ; 
           [0036]      FIG. 8  is a schematic sectioned side elevation of a modification of the forward portion of  FIG. 7 ; 
           [0037]      FIG. 9  is a schematic sectioned side elevation of a modification of the device of  FIG. 1 ; 
           [0038]      FIG. 10  is a schematic sectioned side elevation of a further modification of the device of  FIG. 1 ; and 
           [0039]      FIG. 11  is a schematic side elevation of a modification of the device of  FIG. 1 ; 
           [0040]      FIG. 12  is a schematic sectioned side elevation of the device of  FIG. 11 ; and 
           [0041]      FIG. 13  is a schematic enlarged sectioned side elevation of a forward portion of the device of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0042]    In the accompanying drawings there is schematically depicted a syringe  10  and a retractable needle device  11 . The syringe  10  includes a hollow body  12  of generally cylindrical configuration having an internal bore  13 . The bore  13  slidably receives a piston  14  that sealingly engages the bore  13  so as to generally enclose a chamber  15  having a liquid medication to be delivered. Extending rearwardly from the piston  14  is a piston rod  16 . The forward end of the body  11  tapers to a frusto-conical end  17  surrounding a passage  18 . Typically the frusto-conical end  17  would engage a needle mounting and needle if the syringe  10  was to be used without the device  11 . In such an arrangement an operator would cause longitudinal movement of the piston  14  by pushing the piston rod  16  toward the end  17 . As the volume of the chamber  15  is reduced, liquid in the chamber  15  is forced outwardly through the passage  18 . 
         [0043]    Operatively associated with the syringe  10  is the syringe device  11 . The syringe device  11  includes an elongated hollow body  19  again of generally cylindrical configuration and having a longitudinally extending bore  20 . The body  19  has a forward end  21  and a rear end  22 , with the forward end  21  releasably containing a needle assembly  23 . The needle assembly  23  includes a needle mounting  24  to which there is attached a needle  25 . 
         [0044]    The body  19  includes at its forward end  21  a cap  27  that is elongated and houses a spring  26 . The spring  26  (resilient member) is compressed between the forward portion of the cap  27  and the needle mounting  24  to urge the needle mounting  24  in a direction of the arrow  28 . Extending between the mounting  24  and an internal surface  29  of the body  19  is a seal  30  that sealingly closes the forward end  21 . 
         [0045]    The body  19  encloses a chamber  31  within which the needle assembly  23  is to be received so as to be contained within the body  19 . 
         [0046]    The spring  26  urges the needle assembly  23  in the direction of the arrow  28  so that the needle  25  does not project forward beyond the forward extremity of the cap  27  when the assembly  23  is released. 
         [0047]    The mounting  24  is retained in the position shown in  FIG. 7  by means of a clip  36 . The clip  36  of this embodiment is a resilient clip consisting of a split ring that is radially contracted relative to the longitudinal axis  37  from an expanded configuration to a retracted configuration, with the clip  36  in the retracted configuration releasing the mounting  24 . In this respect the body  19  has a plurality of radially inwardly projecting ridges  38  that engage the clip  36  when the clip  36  is in the expanded configuration to thereby retain the mounting  24  in the position shown in  FIG. 7 . However when the clip  36  is radially contracted it is released from the projections  38  to thereby release the mounting  24 . The clip  36  is caused to contract by engagement with a release member  34 . 
         [0048]    The release member  34  includes a clip engaging part in the form of a body  46  with a plurality of forwardly extending fingers  39  that pass between the projections  38  and engage the clip  36  to cause contraction thereof. Each of the fingers  39  has an inclined (ramp) surface  40  that engages the clip  36  to cause contraction thereof. 
         [0049]    The release member  34  includes a base  33  having a forward part engaging the body  46  by means of a resilient clip  41 . In this embodiment the clip  41  is a split ring. The clip  41  is retained in a groove  42  formed in the body  46  and is radially compressible to release the body  42  from the base  33 . More particularly the clip  41  is received in a recess  43  of the base  33 . The base  33  is a hollow body that has an internal space  48  that receives at least the mounting  24  and a significant portion of the needle  25 , together with the body  46 . The body  46  generally closes the space  48  so that the liquid being injected cannot enter the space  48  while the mounting is attached to the body  19 . 
         [0050]    The rear end  22  of the device  11  is provided with a socket  44  that expands radially outward in a rearward direction and through which a stem  45  of a rear part of the base  33  projects. 
         [0051]    In operation of the above described syringe  10  and device  11 , a user engages the syringe  10  with the device  11  by inserting the end  17  in the socket  44 . The stem  45  projects into the body  12 . The piston rod  16  is moved to reduce the volume of the chamber  15  so that the liquid contained in the chamber  15  is caused to enter the chamber  31  and pass between the body  19  and base  33 . Air is then expelled from the syringe device  11  through the needle  25 . Further movement of the piston rod  16  and therefore piston  14  to reduce the volume of the chamber  15 , causes the liquid in the chamber  15  to pass through the chamber  31  and exit via the needle  25 . 
         [0052]    Upon the piston  14  approaching the full extent of its travel, the piston  14  engages the stem  45  and causes movement of the release member  34  from its rear position (first position) to its forward position (second position) as shown in  FIGS. 3 and 4 . When the release member  34  is moved to its forward position, the fingers  39  engage the clip  36  and cause it to contract thereby releasing the mounting  24 . The spring  26  then moves the needle assembly  35  so that it is contained with the body  19 , that is, with the needle  25  not projecting beyond the cap  27 . However for the mounting  24  to move into the chamber  31 , the body  46  must be released from the base  33 . This is caused by the fingers  40  being prevented from further forward movement by engagement with the mounting  24  after having released the clip  36 . However upon the user continuing to apply pressure to the piston rod  16 , the base  33  is caused to move forwardly so that the annular ramp surface  47  of the base  33  causes radial contraction of the clip  41  to release the body  46  from the base  33 . Accordingly, the spring  26  also causes the member  34  to move rearwardly with respect to the chamber  31 . 
         [0053]    Initially the needle would be covered by a cover  56 . 
         [0054]    In the embodiment of  FIG. 8 , the clip  36  is of a moulded plastics material and includes a head  50  that engages the projections  38 . Extending rearwardly from the head  50  is a tapering portion  51 , with the portion  51  and head being of a generally “frusto-conical” configuration but having a longitudinal slot  52 . The body  46  has an annular recess  53  that receives the clip  41 . In this embodiment the clip  41  is a resilient “O-ring” that also sealingly closes the space  48  enclosed within the base  33 . The “O-ring” is formed of resilient plastics material so as to be compressible. The clip  46  has a frusto-conical internal surface  54  configured to engage the tapering portion  52  to cause radial contraction (relative to the longitudinal axis  37 ) of the clip  36  and in particular the head  50  so that the head  50  is removed from engagement with the projections  38 . This allows movement of the mounting  24  into the base  33  together with at least the majority of the needle  25 . As best seen in  FIG. 8 , there is an annular space  55  between the body  12  and base  33  to provide for the flow of the liquid medication from the syringe  10  to the needle  25 . In this respect it should be appreciated the space  48  is sealingly closed by the clip  41 . However when the clip  36  is contracted and the body  46  prevented from any further forward movement, the clip  41  is resiliently deformed so that the body  46  is released and enters the space  48  due to further forward movement of the base  33 . 
         [0055]    The above described preferred embodiments of the device  11  are intended to be used with luer slip and ( FIG. 9 ) luer lock ( FIG. 10 ) disposable, non-disposable and pre filled syringes. 
         [0056]    In  FIG. 9  a modification of the device  11  of  FIG. 1  is illustrated. In this embodiment the device  11  includes a luer slip arrangement in that it has the socket  44  with a tapering “frusto-conical” surface  60 . The surface  60  engages the frusto-conical surface  61  of the end  17 . The surfaces  60  and  61  are complimentary and frictionally engaged to securely connect the syringe  10  with the device  11 . 
         [0057]    In the embodiment of  FIG. 10  the device  11  is adapted to engage the syringe  10  by means of a “luer lock”. In this embodiment the socket  44  has an annular flange  62  that engages with the threads  63  that project radially inwardly from a cylindrical flange  64  extending forwardly and coaxially from the body  12 . The flange  64  cooperates with the end  17  to provide a cavity  65  that receives the flange  62 . When the flange  62  engages the threads  63  the flange  62  is deformed so as to threadably engage the thread  63  and securely connect the device  11  with the syringe  10  by relative rotation of the device  11  with respect to the syringe  10  about the longitudinal axis  37 . 
         [0058]    In the embodiment of  FIGS. 11 to 13  there is schematically depicted a modification of the device  11 . In this embodiment, the body  19  has a rearwardly projecting annular flange  70  to threadably engage an internally threaded similar flange or a modified form of the syringe  10 . A cover  71  is provided, that is removed when the syringe  10  is to be engaged. 
         [0059]    In this embodiment the mounting  24  has an annular flange  72  with a radially extending portion  73  that engages an annular lip  74  of a forward portion of the base  33 . The annular flange  72  is at a rear portion of the mounting  24 . The annular flange  72  sealingly engages the lip  74  so as to sealingly close the space  48 . 
         [0060]    When the stem  45  is engaged by the syringe  10  so as to move the release member  34  towards the mounting  24 , the base  3  at adjacent the lip  74  is resiliently deformed radially outward, together with resilient inward deformation of the flange  72 , to release the mounting  24  with respect to the base  33  and the body  19 . As the mounting  24  moves in the direction of the arrow  28  relative to the body  19 , the seal  30  moves past the circular step  75  in the mounting  24  to thereby facilitate movement of the needle assembly  23  into the space  48  and therefore the chamber  31 . In this embodiment, the needle assembly  23  is retained in the operative position by being urged in the direction of the arrow  28  so as to abut the lip  74 . 
         [0061]    The chamber  31  extends to a passage  76  that provides for flow of the liquid being injected to the interior of the needle  25 .