| 摘要 |
<p>A disposable safety syringe, which includes an outer sleeve (5), a needle (1), a needle seat (2), a piston (4) and a core rod (6). The rear part of the needle seat (2) is a puncture cone (21) with an annular protrusion (22), which is fixed into the outer sleeve (5) by a sealing expandable loop (3). A membrane area (41) is provided at the front end surface of the piston (4). A cavity (62) is provided in the front part of the push board (61) of the core rod (6). When the injection is ended, the core rod (6) pushes ahead the piston (4) and the sealing expandable loop (3), and the annular protrusion (22) at the rear part of the needle seat (2) is tightly matched with the cavity (62) at the front part of the push board (61) of the core rod (6), then the needle seat (2) can be drawn into the out sleeve (5). A locking loop (7) is provided at the rear part of the out sleeve (5). A cone-shaped stop boss (71) is provide on the outer wall of the locking loop (7). A positioning groove (76) is provided on the inner wall of the locking loop (7). A positioning boss (63) cooperating with the positioning groove (76) is correspondly provided on the core rod (6).</p> |
