| 摘要 |
<p>An automatic retracting safe injector comprises an outer sleeve (2), a piston (8), a core bar (9), a needle head assembly (11) and a sheath (1). The needle head assembly (11) has a needle tube (5), a needle tube seat (6), a needle tube seat clamping ring (7), a sealing ring (3) and a spring (4). The needle tube seat (6) is movably mounted within the front part of the outer sleeve (2), and fixed by an elastic damping claw (7-2) of the needle tube seat clamping ring (7), the spring (4) is sleeved on the front part of the needle tube seat (6). The core bar (9) has tubular structure, and its protruding part is engaged with the elastic damping claw (7-2) of the needle tube seat clamping ring (7). A jam (10) is mounted at the forward end of the core bar (9), and an engaging cavity (10-3) mating with an engaging column (6-1) at the rear end of the needle tube seat (6) is formed on the jam (10). A core bar locking ring (12) is mounted within a rear part of the outer sleeve (2). When one-time injection is done, an elastic damping claw (12-5) of the core bar locking ring (12) resists against a locking lug boss (9-3) of the core bar (9), thus preventing the core bar (9) from being drawn backwards.</p> |
