Automatic sequential fluid flow apparatus

Claim 1

In combination with an intravenous administration set having interconnected primary solution container, calibrated volumetric chamber, and drip chamber for infusion of primary solution into a patient's body, an improvement for controlling non-mixing sequential fluid flow comprising float valve means positioned within the calibrated volumetric chamber operably controlling the primary solution entering the calibrated volumetric chamber, said float valve means defining a float element and a needle valve assembly operatively connected thereto, said needle valve assembly being connected in fluid communication with said primary solution container and being situated upstream from said float element so as to be operated by the buoyant movement of the float element, and said float element constructed to conform to the bottom and sides of the calibrated chamber, said float element so arranged with said needle valve assembly to float in close proximity to said calibrated volumetric chamber bottom; and means introducing a secondary solution into the said chamber, said means including a secondary solution container, tubing interconnecting said secondary solution container and the calibrated chamber, and a flow valve disposed in said tubing, said float valve means operably controlled by the secondary solution in the calibrated chamber whereby the flow of the secondary solution into the calibrated chamber may be controlled by the secondary solution flow valve in order that minimum secondary solution present in the calibrated chamber operates said float, and said float valve means controls the entry of primary solution into the calibrated chamber through said needle valve assembly following termination of secondary solution with minimum mixing of solutions.