PISTON STEM UNDERSTANDING AT LEAST THREE ANNULAR ELEMENTS FOR A PRE-LOADED SYRINGE

摘要

The present invention relates to a plunger rod for a syringe barrel which is preloaded with a medical fluid and for a preloaded syringe comprising such a syringe rod. the pre-filled syringe (20) comprises the following components: a syringe body (8) charged with a medical fluid (10) which has a nozzle (9) on one front side, the nozzle being closed with a cap ( 11), and which is closed on a rear side with a displaceable piston (12); and a plunger rod (15 ', 15' ', 15' '', 15 '' '') which can be inserted into the syringe body (8) via the rear side, said plunger rod having a portion of connection (1) on a front side, through which the piston rod (15 ', 15' ', 15' '', 15 '' '') can be connected with the piston (12). according to the invention at least three annular elements (2a, 2b, 2c) which extend at least in some sections around a longitudinal axis of the piston rod (15 ', 15' ', 15' ' ', 15' '' '), are arranged on a rear side of the connecting part (1) on the piston rod (15', 15 '', 15 '' ', 15' '' ') in such a manner that they are located in the syringe body when the plunger rod (15 ', 15' ', 15' '', 15 '' '') is fully connected with the plunger (12). The three annular elements support a coaxial connection of the plunger rod with the plunger positioned on the syringe. When connecting the plunger rod to the plunger, the three annular elements allow the user a haptic and / or acoustic control to properly connect the plunger rod with the plunger.