fig1 a depicts three elements of the needleless transfer system made possible by the valve of the present invention , medication container 10 , valved stopper 12 , and needleless syringe 11 , with the fourth element , injection port 17 connected to an iv tube 27 , being shown in fig1 b . valved stopper 12 has a member which has been designed to be engaged and actuated by blunt , tubular nozzle portion 13 of needleless syringe 11 . fig1 b depicts nozzle portion 13 with luer being received within neck 19 of injection port 17 . the key element of this needleless transfer system is the valve 20 . it is important that this component work effectively but be capable of being manufactured inexpensively . health and safety of hospital workers is of vital importance , but if they come with too high a price tag , the resistance to change , coupled with inertia , may be too great for a new system to overcome . further , in order to deal with the inertia problem , it is important that the system chosen to initiate widespread usage of needleless systems be capable of usage with conventional needle - bearing syringes . accordingly , the bulk of this description is directed to detailing the features and characteristics of valve 20 which is a highly economic system having the desired characteristics . a first preferred embodiment of valve 20 is shown in fig2 a - c . in these figures , valve 20 is depicted as part of a stopper 12 for a medication container . it will be appreciated that for other applications , the valve will be housed in a simple cylindrical sleeve which may be formed as an integral part of the element with which it operates or as a separate element that can be connected to the element ( i . e ., retrofit ). this stopper 12 includes a first outer member 14 having a first portion 36 shaped to fit snugly within bottle 10 and flange 38 to overlie the mouth of container 10 and a second inner member 16 which contains the operative valve element 20 . preferably , the first outer member 14 is made of an elastomer and may be provided with a protruding ridge ( not shown ) to improve sealing within container 10 and the inner member 16 is made of a moldable plastic material . inner member 16 is most preferably made of two portions 18 and 18 &# 39 ; which may be bonded together , for ease of assembly . valve assembly 20 includes actuator 22 slidably mounted within inner member 16 and an elastomeric membrane 24 whose outer periphery is fixed with respect to inner member 16 and has a pre - formed slit 26 therethrough . membrane 24 is regarded as relatively thick , that is , having a larger than normal thickness to diameter ratio . it is preferred that the thickness fall in the range of between 25 and 75 % of the membrane diameter and more preferably , in the 40 to 50 % range . one exemplary membrane 24 had a thickness which calculated to be 30 % of its diameter in the preinstalled condition , but once inserted into the housing 18 and radially compressed , computed to be more on the order of 40 % of its diameter . slit 26 is normally closed and , in the closed position , prevents egress of medication and ingress of air or other fluids . sliding of actuator 22 may be facilitated by a coating of teflon ® polymer , or the like on one of the relatively slidable elements or by forming contact - reducing ribs 40 on one of the contacting surfaces . by way of example , fig2 c depicts the external surface of slide 22 as having six protrusions which reduce the surface area contact with element 18 thereby resulting in reducing the frictional resistance to movement . as shown in fig2 b , nozzle portion 13 of needleless syringe 11 is received in the trailing end 21 of actuator 22 and is advanced such that leading end 23 pushes through slit 26 . trailing end 21 is sized such that nozzle 13 has an interference fit therewith . in this embodiment , slit 26 may merely be a short longitudinal cut through the thick membrane 24 , although more elaborate designs may be used , as well . leading end 23 of actuator 22 causes the elastomer to bulge as it forces its way through . when syringe 11 has a proper dosage of medication , withdrawal of nozzle portion 13 from neck 19 of container 10 will provide a retraction force on actuator 22 as a result of the interference fit with trailing end 21 , which coupled with the restoring force of elastomeric membrane 24 acting against the tapered surface of leading end 23 , will return actuator 22 to its at rest position ( fig2 a ). should the combination of these forces prove inadequate in certain applications , any of a variety of restorative spring members ( not shown ) can be used . depicted in fig3 is an air vent 30 . air vent 30 includes a hole 32 through inner member 16 and a molded flapper valve 34 formed in outer elastomeric member 14 . flapper valve 34 is a one - way valve which prevents medication from flowing out but permits the influx of air to aid in medication withdrawal by syringe 11 . such a feature may be required on the larger containers 10 to permit adequate passive insufflation for medication withdrawal . passive insufflation is contrasted with the forced insufflation initiated by the syringe during normal withdrawal procedures . it should be noted that one of the benefits of the valved container 10 made possible by the valve of the present invention is the provision of multiple - dose containers which can significantly reduce the per administration cost of medication to the patient . it will be appreciated that many of the other applications for the valve of the present invention ( particularly those involving only injections ), will not require air vents . also depicted in fig3 is the use of the valve 20 of the present invention with a needled syringe . needle 37 will be guided by tapering surfaces of slide 22 to slit 26 . the opening in leading end 23 of slide 22 will preferably accommodate up to an 18 gauge needle . thick membrane 24 will resist puncturing by needle 37 and will , therefore , not easily be broken into pieces as might occur with a thinner membrane . fig4 depicts a trocar unit 60 employing the valve design of the present invention which may be affixed to a conventional medication container 10 by axially pushing spike 62 through conventional stopper 61 establishing a passageway between opening 64 and valve member 20 . in this manner , the valve 20 of the present invention can be retrofit onto any current medication container . plastic cap 66 which may be integrally molded with housing 18 of valve 20 , will snap over the mouth of bottle 10 . a number of the possible uses for the valve of the present invention are depicted in fig1 c . valve 20 of the present invention could be utilized in both the spike port 42 and injection port 44 of the iv bag 46 , at each of the injection ports 48 of the iv tube 50 , the stop cock injection port 52 of the iv line 50 (: as discussed in detail below ), the sampling port 54 , and the iv needle 56 itself . as alluded to earlier , each element may be premanufactured with the valve 20 built into it , or the valve mechanism 20 may be retrofit using a clip on element . fig5 depicts the valve 20 of the present invention incorporated into an iv line stop cock 70 . stop cock 70 has a handle 72 which may be positioned in either of two positions to direct the injected flow primarily upstream or down , as may be desired . fig6 shows a trocar unit 74 which can be connected to any of the injection ports 44 of the iv line . spring finger 76 created by j - slot 78 can snap around iv line 50 and secure trocar unit in place over injection port 48 after needle 78 has penetrated the port cover membrane 63 ( see fig7 ). as mentioned earlier , while it would be preferable to form the valve mechanism 20 as an integral part of each element with which it is to be used , the use of these snap on devices permits the present valve to be used with existing equipment by a retrofit technique . various changes , alternatives and modifications will become apparent to a person of ordinary skill in the art following a reading of the foregoing specification . it is intended that all such changes , alternatives and modifications as fall within the scope of the appended claims be considered part of the present invention .
a valve which can be used to facilitate needleless transfer of medication from the container to a patient . a slidable actuator is engaged by the nozzle portion of a syringe and the tapered lead portion of the slide is forced into the container through a pre - slit elastomeric membrane . the membrane is relatively thick , preferably between 25 and 75 % the width dimension of the membrane and , more preferably , between 40 and 50 % of that dimension . the thick membrane is durable enough to withstand repeated usage and damage resistant enough to permit use with needled syringes .