Patent ID: 7988663

Claim:
A syringe including a retractable needle comprising: a barrel having a fluid chamber defining a longitudinal axis and including a proximal end, and a distal end adapted to be attached to a needle; a plunger rod having a distal end and proximal end, the plunger rod including an inner sleeve slidably engageable with an outer housing, the inner and outer housing being axially moveable with respect to each other upon activation of a decoupling element associated with the plunger rod; and a compressible stopper mounted on the distal end of the of the plunger rod, the stopper being configured such that when distal force is applied to the plunger rod, the stopper is compressed in the direction of the longitudinal axis in an amount to allow distal movement of the plunger rod along the longitudinal axis a distance sufficient to permit activation of the decoupling element, causing the inner sleeve to decouple from the outer housing and move distally with respect to the outer housing and retraction of the needle within the syringe barrel, wherein the decoupling element includes one or more flexible fingers formed on the inner sleeve of the plunger rod and the barrel includes an inner surface and a shoulder formed on the inner surface adjacent the proximal end adapted to engage a contact surface on the inner sleeve of the plunger rod, causing the one or more flexible fingers to flex inwardly and permit relative distal movement between the outer housing and inner sleeve.