Shielded hypodermic syringe

摘要

A hypodermic syringe comprising a barrel, a needle coupled to the barrel and terminating in a point and a needle guard mounted on the barrel for movement between an extended position in which the guard shields the needle and a retracted position in which the guard does not shield the needle. The guard can be releasably locked in the retracted position and locked in the extended position. Locking of the guard is accomplished by a track on the internal surface of the guard and track-engaging members on the barrel.