Patent ID: 8864706
Filing Date: 2014-10-21
Classification: A61M

Abstract:
1. A retractable syringe comprising: a barrel; a needle unit comprising a needle, an interior of the needle being in fluid communication with a chamber within the barrel; a retention mechanism for retaining the needle unit at one end of the barrel; a hollow plunger movable within the barrel towards the needle unit; a drive mechanism for driving the needle unit into the plunger; and a cutting crown at the end of the plunger facing the needle unit, the cutting crown being arranged for cutting the retention mechanism as the plunger is advanced, so that the drive mechanism retracts the needle unit into the barrel; the profile of the cutting crown including at least two cutting teeth which cut a first portion of the retention mechanism before other portions of the cutting crown cut other portions of the retention mechanism, the at least two cutting teeth having interspaced between each consecutive cutting tooth an arcuate bridge spanning from tooth to tooth.