Intermixing syringe

Claim 1

An intermixing syringe for the isolated storage of at least two medicant portions and the like, the syringe including an outer housing in whose interior front end is stored one of the medicant portions and a hollow plunger in whose bore there is a slidable piston and in its hollow portion of the plunger is the isolated storage of the other stored medicant Portion, the syringe including means whereby the medicant portion carried by the plunger may be transferred from the hollow plunger to the interior front end of the outer housing for the mixing of the portions in the front end of the outer housing, the syringe having means for bringing the stored medicant portion in the plunger into the front end of the outer housing and the front end of the same housing portion into a condition of reduced pressure, the syringe comprising: (a) an outer housing of generally tubular configuration having an open rear end extending into an inner bore of a generally constant cross section, the housing having a front partially closed other end with a discharge passageway therethrough; (b) removable means for closing the passageway of the partially closed front end of the housing so as to prevent the passage of air, fluids and the like; (c) a plunger having a main portion of generally tubular configuration and sized to easily move axially in the bore of outer housing without sealing of the bore of the housing; (d) a movable piston providing for the closing of the rear end of the plunger and the hollow portion thereof to the passage of air, fluid and the like, said movable piston slidable within and through the length of an interior bore formed in the plunger and providing therewith a fluid-tight sealing means, and (e) a resilient piston adapted for mounting on and closing the front end of the plunger, said piston formed with a plurality of ring-like sealing surfaces sized so as to be slidable in the bore of the housing while engaging said bore in a fluid-flow sealing manner, the piston having at least one flow passageway formed therein with one end of the passageway open to the interior of the plunger and the other end terminating at the piston outer surface and between adjacent ring-like sealing surfaces, said piston further formed so that under the influence of a reduced pressure developed in the forward portion of the outer housing those ring-like sealing surfaces forward of the formed flow passageway are deflectable forwardly from a sealing condition to a fluid-flow forwardly condition permitting the fluid in the plunger to flow through said passageway and past those forward sealing surfaces and into the forward housing portion when said forward housing portion is brought to a condition of reduced pressure as developed by the rearward movement of the plunger in the outer housing.