| 摘要 |
A syringe (10) for drawing blood from a patient, the syringe having a barrel (12) with a restricted free end (12a) and a needle assembly (14) releasably secured to the restricted free end. A plunger (16) is inserted into the barrel through an opposed end (12b), and retraction of the plunger within the barrel, away from the restricted free end, is effective to withdraw blood from the patient when a needle (14a) with a sharpened free end of the needle assembly is appropriately inserted into the patient. The syringe 10 is also provided with an annular needle guard (18) that surrounds the barrel and is slidable with respect thereto between a first position, in which the needle guard does not surround the needle, and a second position, in which the needle guard does surround the needle, to prevent the tip of the needle from injuring a person handling the syringe during times when the syringe is not being used to withdraw blood from a patient. The needle guard is made from a semi-rigid, transparent organic material, and has a diametrically opposed pair of inwardly extending projections (18a) that engage a diametrically opposed pair of outwardly facing recesses (14a) in the needle assembly when the needle guard is in its first position to prevent it from inadvertently moving to its second position. Hand squeezing of the needle guard along an axis extending perpendicularly to an axis between the projections is effective to disengage the projections and recesses, whereupon relative motion can occur between the barrel and the needle guard. |
