Patent ID: 7544180

Claim:
A syringe assembly comprising: a syringe comprising a barrel having an open proximal end and a barrel end surface at a distal end, a plunger slidably disposed in the barrel comprising a push flange, and a plunger tip comprising a plunger tip end surface positioned on a distal end of the plunger; the push flange being spaced apart from the plunger tip end surface by a first distance; a sheath unit comprising a sheath cover telescopically disposed over and removably secured to an inner shell; said inner shell comprising an interior surface defining an interior cavity; a spring compressed by a shoulder on the sheath cover and a shoulder on the inner shell; wherein the barrel is disposed, at least in part, in the cavity of the inner shell; and wherein the plunger comprises three plunger positions including a first plunger position in which the plunger tip positioned on the plunger is spaced apart from the barrel end surface; a second plunger position in which the plunger tip contacts the barrel end surface; and a third plunger position in which the push flange on the plunger moves a distal direction relative to the plunger tip distal end surface such that the push flange is now spaced apart from the plunger tip distal end surface by a second distance, which is less than the first distance.