Abstract:
Apparatus  10  for the removal of a needle N from a syringe S and comprising a housing  13  having an opening  119  for insertion of a needle assembly A, a needle receiving socket  47  aligned with the opening  119.  The socket  47  is formed from a pair of jaws  47  and having a central cavity with an internal profile  54  shaped to receive a needle hub H and accommodate the needle N, the jaws  47  move together to grip the needle hub H and move apart to eject the unscrewed needle assembly A, the whole socket  47  being rotatable to unscrew the needle assembly.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention is a means of safely removing used needles from the body of a multi-use syringe and single use syringe without the need to undo and remove the needle manually  
       BACKGROUND OF THE INVENTION  
       [0002]     Multi-use and single use syringes are used in medicine, veterinary practice and in dentistry. In dentistry multi-use syringes are used for the administration of anaesthetic injections into the mouth, or may be used for mass-vaccination programs. Devices are known for the removal of used disposable needles from the syringe. Typically a needle disposal container may be provided with a lid having a shaped aperture for engagement with a needle hub. The technician or nurse carefully inserts the needle into the aperture so that the needle hub is held stationary within the aperture and then unscrews the syringe from the needle hub and the needle drops into the disposal container.  
         [0003]     In another known apparatus shown in FR 2609401, there is disclosed a disposal container fitted with a needle gripping device that facilitates needle removal. EP-A-0838 228 discloses a motorised needle removal device which uses serrated arms for engaging the needle hub for unscrewing the needle. The needles then fall freely into the container after removal. However, if the frictional engagement is insufficient to unscrew the needle hub then the needle will remain in place. An alternative unscrewing action is shown in U.S. Pat. No. 5,531,323 in which a rotatable gear wheel engages the external surface of the needle hub.  
         [0004]     The applicants earlier patent application GB-A-2376 892 describes apparatus for the removal of a needle assembly having a needle hub which is screw-threadably engaged with a syringe, said apparatus comprising a housing having an opening for insertion of the needle assembly and adjacent portion of the syringe, a socket mounted within the body in alignment with the opening, said socket having a cavity internally shaped to receive the hub and a coaxial through-bore to accommodate the needle, the socket holding the hub rotationally fast relative thereto allowing the syringe to be unscrewed from the needle assembly, and an ejector means located in the housing for ejecting the unscrewed needle assembly from the socket into a collection container located within the body.  
         [0005]     The present invention provides an automatic needle removal device in which the needle is removed from the syringe body by rotation of the needle hub and is collected in a collection bin and which is a development of the earlier apparatus described above.  
       STATEMENTS OF THE INVENTION  
       [0006]     According to the present invention there is provided apparatus for the removal of a needle assembly from the body of a syringe, said apparatus comprising a housing having an opening for insertion of the needle assembly and adjacent portion of the syringe, a needle receiving socket mounted within the body in alignment with the opening, said socket having a cavity internally shaped to receive the needle hub and accommodate the needle, the socket holding the hub rotationally fast relative thereto and being rotatable relative to the syringe to remove the needle assembly from the syringe, wherein the socket is formed from at least two jaws which are moved together to grip the needle hub to facilitate unscrewing of the needle hub and which are moved apart to eject the removed needle assembly into a collection bin.  
         [0007]     The term syringe covers both syringes with disposable plastic bodies typically having push on needle hubs and multi-use re-usable syringes, typically made of metal and/or glass and having screw on needle hubs.  
         [0008]     Preferably the socket comprises two semi-circular jaws which are rotated by cam means which close the jaws in one direction of rotation relative to the socket to remove the needle assembly and which open the jaws in the reverse direction of rotation. The two jaws may also be biased apart by spring means.  
         [0009]     Preferably the jaws have an internal profile shaped to accommodate a plurality of different sized hubs.  
         [0010]     The jaws may be located in a housing which is rotated by a motor, the housing being capable of limited rotational movement relative to the jaws and including cam surfaces which act on the jaws during said limited rotational movement to open and close the jaws.  
         [0011]     The motor is a suitable electrical bi-directional motor which rotates the housing through a gear train clamp the hub and unscrew the hub from the needle body in one direction and release the hub in the other direction. The motor is preferably a 12V motor torque sensing motor which may be operated from the mains via a transformer or may be battery operated, preferably using rechargeable batteries.  
         [0012]     Preferably, the housing has a gear formed integrally therewith.  
         [0013]     The motor may be activated by a manual switch means located inside of the opening and which is operated by insertion of the syringe body into said opening. A second manual switch may be located externally of the housing. The apparatus housing in use sits directly on the collection bin, the bin having an aperture for receiving the needle assemblies, and which is provided with a rotatable closure which also serves as the second switch for the motor, the motor being activated when the closure is in an open condition. The motor is operable only when both the switches are closed.  
         [0014]     The housing may connected to the collection bin by a locking means which is unlocked to allow the bin to be removed from the housing for disposal of needle assemblies. Additionally or alternatively, the housing may be connected a resilient clip means on one of the housing and bin which engages a detent on the other of the housing and bin.  
         [0015]     The locking means may also be provided by the closure which when open couples the housing to the bin and closed releases the housing from the collection bin for detachment therefrom.  
         [0016]     The apparatus housing includes a motor support plate which is shaped to locate the motor, the shaped portion of the support plate being received in a like recess formed in the collection bin to facilitate location of the apparatus on the location bin.  
         [0017]     The collection bin may be provided as a part of said apparatus according to the present invention.  
         [0018]     The bin may be made from a suitable plastic material to enable both bin and contents to be incinerated, and for withstanding elevated temperatures used for cleaning 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0019]     The invention will be described by way of example and with reference to the accompanying drawings in which:  
         [0020]      FIG. 1  is an isometric view of apparatus according to the present invention also showing the insertion of a syringe and needle;  
         [0021]      FIG. 2  is an exploded isometric view of the apparatus of  FIG. 1 ;  
         [0022]      FIG. 3  is a plan view of the apparatus of  FIG. 1  with the housing removed to show the drive mechanism for the needle receiving socket;  
         [0023]      FIG. 4  is a section on the line  4 - 4  of  FIG. 3 ;  
         [0024]      FIG. 5  is a section on the line  5 - 5  of  FIG. 3 ;  
         [0025]      FIG. 6  is a side elevation of the apparatus with the housing removed to show the internal workings; and  
         [0026]      FIG. 7  is an exploded isometric view showing the needle removal assembly in an assembled condition. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]     With reference to  FIG. 1 , there is shown a typical dental syringe S, having a needle assembly A, screwed onto the body B of the syringe. The needle assembly comprises needle N which is mounted within a hub H which screws onto the body B. Disposable needle assemblies A are removable from the body by gripping or holding the external surface of the hub H and unscrewing.  
         [0028]     With reference also to  FIG. 7 , the needle assembly A is removed from the re-usable syringe S using the needle remover apparatus  10 . The syringe S may be used for medical, dental or veterinary purposes. The apparatus  10  is formed in two distinct parts, a needle remover  11  and a collection bin  12  on which the needle remover  11  sits. The needle remover  11  comprises a hollow housing  13  and a sub-assembly  14 .  
         [0029]     Referring now to  FIGS. 2-6  also, the sub assembly  14  comprises a base plate  21  which has a recess  23  therein and supports an upright PCB (printed circuit board)  31  on its inner side. The recess  23  in use locates in a like recess  16  in the top surface  15  of the bin  12  and houses an electric motor  24  in an upright condition. Also located on the base plate  21  is a electrical power socket  25  for a power connection to the PCB  31 . The PCB  31  includes an AC/DC transformer  26 , electrical contacts  27 ,  28 , and programmable microprocessor (not shown) for control of the motor  24 . The motor  24  is held in its upright position and has a shaft with a drive gear  51  attached thereto.  
         [0030]     A switch plate  32  sits on the upper surface  15  of the bin  12  to the side of the base plate  21  and includes an arcuate clip portion  34  which in use clips around a raised circular boss  19  on the upper surface  15  of the bin  12 . The boss  19  has an aperture  20  therein and has a closure  17  mounted on the boss for opening and closing the aperture  20 . The switch plate  32  includes a leg  33  which is engageable with a contact  27  for operation of the motor  24  and a tab  35  which in use engages a recess  18  in the outer surface of the closure  17  such that rotation of the closure  17  on the boss  19  causes the lug  33  to open or close the contact  27 .  
         [0031]     A gripping jaw assembly  40  for gripping the needle hub H is mounted above the closure  17 . The assembly  40  includes a base plate  41  on which a housing  42  for the jaws is rotatably mounted. The base plate  41  in use clips into the housing  42 . The jaw housing  42  comprises a cylindrical hollow body  43  having a coaxial outer flange  50  with a gear  44  on its radially outer surface, and annular cam plates  45 , 46  at its upper and lower ends. A pair of arcuate jaws  47  are located within coaxially within the cylindrical housing  42 . The two jaws  47  are biased apart by four springs  48  and may additionally also be biased apart by a spiral spring  49 . The upper and lower ends of the two jaws  47  are provided with lugs or pins  52  which engage cam surfaces provided in slots  53  (see  FIG. 2 ) in the respective cam plates  45   46 . Rotation of the housing  42  relative to the jaws  47  causes the lugs  52  to move along the slots  53  simultaneously moving the jaws  47  radially relative to the axis of rotation of the housing  42 .  
         [0032]     The two jaws  47  each have a guide plate  55  thereon to assist and guide movement of the jaws  47  towards and way from each other. The jaws  47  form a generally cylindrical socket located within the housing  13  in alignment with an opening  119  in the top surface of the housing  13 . The two jaws  47  form a split open ended socket having a internal stepped profile  54  (see  FIG. 4 ) which can accept a plurality of different sized needle hubs H. The stepped profile  54  forms a split cavity with the larger diameter portion open to the opening  119  and the smallest diameter portion at the base of the cavity.  
         [0033]     An annular activation plate  61  is slideably mounted on the flange  50  on the housing  42  by means of pins (not shown). The plate  61  is capable of limited axial movement relative to the housing  42  and is biased away from the flange  50  by springs arranged coaxially of the pins. The movement away from the flange  50  may be limited by abutments on the pins. The activation plate  61  fills the opening  119  in the housing  13  and has a downwardly extending conical portion  63  with an aperture  64  in the centre which aligns with the cavity between the jaws  47  and the aperture  119  in the housing  13 . A semi-circular switch means  65  is pivotally mounted to the activation plate  61  and has a dog leg shaped limb  66  thereon which in use activates contact  28  on the PCB  31  causing the motor  24  to operate.  
         [0034]     The housing  42  is caused to rotate by operation of the motor  24 . The motor  24  is preferably a bi-directional motor which is torque sensitive delivering a suitable maximum torque load removal of a needle N. The operation of the motor is controlled by the programmed controller on the PCB  31 . The gear wheel  51  on the motor is connected to the gear  44  on the housing  42  by gears  71 ,  72 , the gear  71  being a reduction gear.  
         [0035]     The PCB  31  may be connected to an LED display  75  on the top of the housing  13  which indicates various stages of operation of the needle remover apparatus  10 .  
         [0036]     In use, the apparatus  10  is first activated by rotation of the closure switch  17  which opens the aperture  20  and causes the leg  33  to close contact  27  on the PCB. This may illuminate a warning LED on the display  75 .  
         [0037]     A needle N is inserted through the opening  119  in the housing  13  and aperture  64  until the needle body B engages the activation plate  61 . Further inward movement of the needle body B depresses the activation plate  61  locating the needle hub H between the jaws  47  and causing the switch means  65  to move the limb  66  to operate contact  28  on the PCB. The needle N passes through the gap between the jaws  47 .  
         [0038]     The closure of contact  28  operates the motor  24  which via gears  51 , 71 , 72  rotates the jaw housing  42  in one direction. The jaws  47  are connected to the housing  42  by the lugs  52  engaging in the slots  53  in the cam plates  45 , 46 . Limited rotation of the housing  42  relative to the jaws  47  moves the lugs along the slots  53  moving the jaws together to clamp the hub H. Once the lugs  52  abut the end of the respective slot  53 , further rotation of the housing  42  unscrews the needle and hub from the syringe body. The motor  24  is programmed to rotate the housing through an appropriate number of rotations over about a 3 sec. time period.  
         [0039]     After the programmed rotation in one direction, the microprocessor operates a warning LED on the display  75  and the syringe S is then removed. The motor  24  operates in the reverse direction opening the jaws  47 . On opening of the jaws, the needle N will eject from the jaws and drop into the collection bin  12 .  
         [0040]     The bin  12  can be removed from the apparatus when full. The closure  17  closes the aperture  20  and the bin and its contents can be disposed of by any suitable method e.g incineration.  
         [0041]     The assembly  40  comprising the jaw housing  42 , activation plate  61  and switch means  65  can be removed from the housing  13  as a unit for cleaning.  
         [0042]     The apparatus may also be used with disposable syringes having needles whose needle hub is a push fit onto the syringe body.