Infusion cannula assembly

Claim 1

An infusion cannula assembly comprising, a three-way valve including a valve body having at least two inlet openings for introduction of infusion fluids and an outlet opening, the openings being disposed radially normal with each other, one of said inlet openings being positioned along a line common with said outlet opening, a catheter sealingly engaged on said outlet opening, the catheter including a connection bracket having a pair of arcuate wings formed integral therewith, a cannula having a puncturing point at one end and a cannula connection tube at the other end, said cannula removably received through said one inlet opening and said catheter, said valve body being of generally cup-shaped configuration with an open top, a valve tap of generally cup-shaped configuration with an open top and bottom, the valve body having a raised extension formed in the bottom thereof defining an annular groove between said extension and the walls of the valve body, said valve tap being sealingly and rotatably mounted in the open top of the valve body with the open bottom of the valve tap disposed within the valve body, the bottom of the valve tap being positioned in said groove to be guided thereby, said valve tap including gate-formed slots opening to the bottom thereof to permit selective introduction of infusion fluids from either or both of said inlet openings, the valve tap including a handle with three radially outstanding pins disposed in corresponding arrangement with said slots such that the disposition of the slots and the resultant flow through the tap valve is indicatEd by said pins, the valve tap forming a mixing chamber within the valve body, said valve tap including a resilient diaphragm positioned over the top thereof and extending therewithin, said diaphragm having a narrow slit on the portion thereof extending within the valve tap, whereby infusion fluids may selectively be introduced under pressure into said assembly through said diaphragm independent of the disposition of the slots in said valve tap, but said diaphragm will otherwise maintain an air-tight seal of said valve tap on said assembly, and annular bulge and groove means positioned between said valve body and valve tap and between said catheter and said outlet opening such that an air-tight seal is formed therebetween to prevent inadvertent entry of air into said assembly.