| Abstract |
Hypodermic syringe or medical sampler has a hollow needle (115) that is automatically retractable after use. A one-piece body (101) mouolding has a main chamber for a plunger 1105) or sampler container or drug cartridge, a forward chamber (1i1) to house a spring (133) to bias a needle holder (117), and internal latching formations (141) to retain the needle holder (117) with the spring (133 compressed in the forward chamber until automatic retraction when the latching formations (141) are released by end of plunger movement. Directo plunger-to-body sealing involves an over size plunger head (105H) forcing head and wall deformation. Both ends of the spring (133) have needle, its holder, spring and seals can be combined with needle lubrications, and retraction prevention with sterilizing tell-tale. The plunger (105) has top and grip formations (105F) for the needle holder (117), and the needle can be double ended for taking samples or emptying drug cartridges. |