| abstract |
A safety syringe having a protective sleeve (40) which is movable between a retracted position wherein the needle (14) is exposed and a locked, extended position wherein the needle (14) is protected. A collar (22) is attached to the distal end of the barrel (10) to selectively engage a key (42) on the shield (40) in the retracted and extended positions. The locking mechanism preferably includes a series of ramps and slots which engage portions of the shield (40) to retain the shield (40) in the retracted and extended positions. The shield (40) slides longitudinally between the retracted and extended positions and, in a preferred embodiment, may be rotated about the barrel (10) of the syringe to irreversibly lock the shield (40) in the extended position. |