Patent ID: 6120479
Filing Date: 2000-09-19
Classification: A61M

Abstract:
An auto-destruct syringe, comprising a syringe barrel (12) for holding a fluid having an open rear end (14) and a closed front end (20) and a passage (23) extending through the closed end of the barrel to permit expulsion of fluid from the interior of the barrel, a piston assembly (50) reciprocatable in the barrel (12) and sealingly engaging the barrel wall, a plunger (80) having a forward portion normally positioned in the barrel (12) and a rearward portion to be manipulated by a user of the syringe, characterized in that the syringe further comprises a deforming mechanism (90) on one of the piston assembly (50) and the plunger (80) for permanently deforming the barrel wall, the deforming mechanism being movable from an at rest position wherein the barrel wall is not deformed by the deforming mechanism to a barrel wall engaging position wherein the barrel wall is permanently deformed by the deforming mechanism;engaging means (87) mounted to the other of the piston assembly (50) and the plunger (80) for forcing the deforming mechanism (90) into the barrel wall engaging position upon rearward movement of the piston assembly; anda connecting structure for connecting the piston assembly (50) with the plunger (80), the connecting structure including a first coupling mechanism (62, 81) for allowing the piston assembly (50) to be moved rearward by pulling back the plunger during an initial aspiration stroke without engagement of the engaging means with the deforming mechanism, and a second coupling mechanism (64, 81) for coupling the piston assembly (50) with the plunger (80) during a second aspiration stroke such that the engaging means (87) engages the deforming mechanism (90).