Patent ID: 6846301

Claim:
A syringe for retracting a needle supported on a needle seat, comprising: a generally tubular body having a needle end and an opposing plunger end, the tubular body having an internal throughbore extending between the needle end and the opposing plunger end, the tubular body sealing receiving the needle seat therein; a seat/body retainer adjacent the needle end of the tubular body for initially attaching the needle seat to the generally tubular body, the needle seat being selectively moveable within the tubular body from an initial retained position to a needle seat retracted position; a plunger having an interior chamber therein and a needle seat end positioned within the internal throughbore of the generally tubular body, the plunger being moveable within the throughbore of the tubular body; a stopper for sealed engagement between the generally tubular body and the plunger; a piston selectively moveable between an initial retained position adjacent the needle seat end of the plunger and a piston retracted position within the plunger; a one-way valve allowing flow from the interior chamber in the plunger to the throughbore in the generally tubular body while preventing fluid flow from the throughbore in the generally tubular body to the interior chamber in the plunger; a seat/piston latch for selective engagement of the needle seat with the piston; and a controllable plug selectively preventing fluid from entering the tubular body through the needle end when in a closed position.