| 摘要 |
<p>A safety syringe comprises a needle set (2), a barrel (1) and a plunger (3). Wherein the front end of the needle set (21) is connected with a needle (22), while the rear end is provided with a first coupling portion (212), the bottom of the needle set has on the periphery thereof at least an annular flange (211). The barrel is hollow, its front end is formed as a socket to connect the needle set; the socket has on its inner wall two mutually neighboring annular flanges (111,112). The rear end of the barrel is used for slipping in the plunger of which the front end has a piston (32); a second coupling portion (33) is provided on the front end of the piston. Hence when the needle set is connected to the needle-set socket (11), the said at least an annular flange on the periphery of the needle set is located between the two annular flanges on the inner wall of the needle-set socket to increase the tightness of connection. When the front end of the plunger is pushed to the topmost position, the first (212) and second (33) coupling portions mutually connect, so that when the plunger is pulled back, the needle set can be pulled back into the barrel.</p> |
