| 摘要 |
<p>A protective device for a removable cannula (50) used with a hypodermic syringe (36) includes an elongate sheath (14) open at one end. A piston (22) in the sheath (14) is slidable longitudinally between an extended position and a retracted position. The removable cannula (50) is on one side of the piston (25), and the hypodermic syringe (36) on the other side. Means are provided for connecting the cannula (50) to the syringe (36) through a bore in the piston (22) so the piston (22) is between the cannula (50) and the syringe barrel (38). With the piston (22) in the extended position, the cannula (50) extends from one end of the sheath (14), and the hypodermic syringe plunger (40) extends from the other end so the assembly is ready to use in the same manner as a conventional hypodermic syringe. After use, the piston (22) is moved to the retracted position so that the scarf end (52) of the cannula (50) is safely enclosed within the sheath (14).</p> |
