Patent ID: 7530966
Filing Date: 2009-05-12
Classification: A61M

Abstract:
1. A syringe comprising: a barrel comprising a gripping flange at a proximal end, an inward projection at a distal end comprising an opening and defining a first internal shoulder, a wall structure comprising an exterior surface and an interior surface defining an interior cavity, and a second internal shoulder positioned closer to the opening at the distal end than the gripping flange at the proximal end; a plunger comprising a tubular body having an interior cavity disposed in the interior cavity of the barrel, a push flange at a proximal end, and a plunger tip holder comprising a push end and a shoulder on the tubular body; a plunger tip mounted on the plunger tip holder, the plunger tip including a distal portion defined by a distal wall, a proximal wall and a generally cylindrical side wall extending between the distal wall and the proximal wall, the distal portion defining an interior space, the plunger tip further including first and second extension legs extending proximally from the proximal wall of the distal portion; a carriage comprising an elongated body having a spring located thereon, a base extending from the elongated body, a shoulder positioned between the elongated body and the base, and a passage comprising a needle attached thereto; wherein the spring is compressed by the first internal shoulder of the barrel and the shoulder on the carriage and the carriage is removably secured to the barrel by wedging a resilient holding tire in between the base of the carriage and the interior surface of the barrel; 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 carriage; a second plunger position in which the plunger tip simultaneously contacts the shoulder on the plunger and the second internal shoulder on the barrel before the holding tire is substantially pushed off of the base of the carriage; and a third plunger position in which the push end on the plunger pushes the holding tire distally off of the base of the carriage; and wherein in the second plunger position, the second internal shoulder on the barrel stops the plunger tip from further distal movement towards the distal end.