Abstract:
A connector for joining a small dose syringe to a large reservoir syringe for filling the small dose syringe from the reservoir syringe. The connector has a tubular female-to-female coupler and there is a protector housing that is spaced radially outward from and extends forwardly beyond the coupler portion that attaches to the small dose syringe, thereby protecting this coupler portion from touch contamination. A removable closure with a recessed plug protects the small dose coupler portion from contamination when not in use.

Description:
BACKGROUND OF THE INVENTION 
     In dispensing liquid medication, pharmacists will often extract liquid medication from a large bottle or vial into a reservoir syringe, such as a large 30 cc syringe, A series of small dose syringes, 3 cc for example, will be sequentially connected to the large reservoir syringe and filled from it. In the example given above, ten small dose syringes can be filled from one charge of the large reservoir syringe. 
     In the past there have been coupling devices for joining the small dose and reservoir syringe during this small dose syringe filling procedure. Some of these have been tubular metal couplers with a tapered female Luer sleeve at each end. 
     There was a problem with these previous tubular couplers because the end of the coupler used to repeatedly connect and disconnect the small dose syringe was exposed for touch contamination by the pharmacist connecting and disconnecting the series of small dose syringes. This could occur when he grasped the tubular coupler in one hand and the small dose syringe in the other to connect, or disconnect, the small dose syringe. 
     SUMMARY OF THE INVENTION 
     We have overcome the problem with the previous tubular couplers by providing a tubular coupler with a protector housing connected to the coupler and this housing is radially spaced outwardly from the coupler. The housing also extends forwardly beyond the coupler end that is connected and disconnected to the small dose syringe. Thus, the pharmacist can grasp the housing for manipulating the connecting and disconnecting of the small dose syringe without ever touching the tubular coupler itself. The housing portion that protrudes beyond the tubular coupler&#39;s forward end acts as a shield preventing inadvertent touching of the forward end of the tubular coupler. 
     Prior to connecting the small dose syringe to the tubular coupler, a removable closure with a protective skirt surrounding a recessed plug closes off the coupler&#39;s forward end to further protect against contamination. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view showing the large reservoir syringe connected to the small dose syringe by the connector of this invention; 
     FIG. 2 is an enlarged sectional view of the connector showing one end joined to the reservoir syringe and a protective cap being removed from a forward portion of the connector; 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 2; 
     FIG. 4 is a sectional view taken along line 4--4 of FIG. 2; and 
     FIG. 5 is an enlarged sectional view of a second embodiment of the invention showing an optional filter in the tubular adapter. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, a large reservoir syringe 2 is filled from a medical liquid vial or bottle. In the drawings a conventional 30 cc syringe is shown as the reservoir syringe and has a conventional internally threaded Luer-lock collar 4. A rear portion of the connector of this invention, shown generically as 6, is connected to Luer-lock collar 4 of the reservoir syringe 2. A forward end of the connector 6 is attached to a small dose syringe 8. With the connection shown in FIG. 1, the small dose syringe can be filled from the reservoir syringe simply by pulling the plunger 10 of the small dose syringe to the right in FIG. 1. This method of filling the small dose syringe is preferred over a method of pushing a plunger 12 of the reservoir syringe to the right in FIG. 1. Pulling plunger 10 rather than pushing plunger 12 gives a more accurately controllable volume in the small dose syringe. 
     As shown in more detail in FIG. 2, the Luer-lock collar 4 surrounds a tapered Luer adapter 14 as is conventional with syringes. The connector includes a tubular coupler 16 with a rear internally tapered female portion 18 that forms a removable liquid-type wedge seal with tapered adapter 14. Laterally protruding ears, such as 20 engage internal threads 22 of Luer-lock collar 4 securely holding tubular adapter to the reservoir syringe. 
     The tubular coupler has a forward end portion 22 with an internal tapered female Luer surface for wedging to a Luer adapter of small dose syringe 8. It is important that the critical forward end 24 of the tubular adapter not be contaminated during connecting and disconnecting a series of small dose syringes. This invention reduces the chance of touch contamination by providing a housing 6 that includes a transverse wall 26 joined to a central portion of tubular adapter 16. The transverse wall 26 is in turn joined to a protective collar 28 that is circumferentially spaced from a forward section 22 of the tubular coupler. Preferably, the outer surface of the protective collar has a diameter more than three times greater than the internal bore of the coupler&#39;s forward section 22. Also, the forward section 22 of the coupler is free of locking ears to engage with a Luer-lock collar of a syringe, so such syringe can be attached and detached with a simple axial motion. A forward end 30 of protective collar 28 will likely engage the pharmacist&#39;s hand or other object preventing it from touching critical front end 24 of the tubular adapter. This front end 24 might contain a liquid drop as a result of disconnecting the small dose syringe 8. 
     Preferably, there is an annular recess between the protective collar 28 and forward section 22 of the coupler of sufficient size to receive a Luer-lock collar of a syringe without interferring contact between the two collars. The size of such Luer-lock collar is shown in FIG. 5. 
     Prior to connecting the small dose syringe 8, a protective closure shown generically as 32 closes off the forward end of the tubular coupler. This closure includes a protective skirt 34 that is circumferentially spaced outwardly from the forward portion 22 of the tubular coupler when the closure is assembled to the tubular coupler. Thus, skirt 34 does not touch the tubular coupler so as not to transfer contamination to and from such coupler. The closure is supported on forward end 22 of the coupler by a recessed plug 36 that is tapered to wedgingly fit the internal surface of the coupler&#39;s forward end portion 22. A rear portion 38 of plug 36 is recessed from a rear end 40 of skirt 34. Because the skirt&#39;s end 40 protrudes beyond the plug&#39;s rear end 38, the skirt acts to protect the plug&#39;s rear end 38 from contamination. To aid in connecting and disconnecting the closure, a flat handle 42 is provided. 
     In the sectional view of FIG. 3, the shape of the protective collar is more clearly shown. Here the collar 28 has a pair of flat sections 44 and 46 to prevent the connector from rolling on a flat surface. For improved gripping, the collar 28 also has a series of longitudinal ribs as indicated at 48. 
     The FIG. 4 view points out the shape of the closure&#39;s handle 42 which includes a pair of flat surfaces 50 and 52 for easy gripping. 
     In FIG. 5, the connector is shown attached to both a reservoir syringe 54 and a small dose syringe 56. In this FIGURE, a second embodiment of the connector is shown with an optional filter 58. Thus, particulate matter that might be within the large reservoir syringe is filtered out prior to its transfer to the small dose syringe 56. All other aspects of the second embodiment of the connector are the same as in the first embodiment. 
     This invention has worked very well when the connector is injection molded with the tubular coupler and the protector housing as an integral one-piece unit. Preferably, both the connector and closure are molded of a polypropylene thermoplastic which has a very high drug compatibility. 
     In the preceding description, specific embodiments have been used to describe this invention. However, it is understood by those skilled in the art that certain modifications can be made to these embodiments without departing from the spririt and scope of the invention.