| 摘要 |
The invention relates to a piston-cylinder unit (1) for a needle-free injector, for example for providing a sterile injection solution, said unit comprising a chamber (3) arranged in a cylinder (2), for receiving an injection solution (4), a front wall (5) having at least one nozzle borehole or an outlet element (6), and a second piston (7) arranged in such a way that it can move in the chamber. Said unit is characterised in that the chamber (3) is made from two parts with a first chamber (8) and a concentric second chamber (9), the cross-section of the first chamber (8) being larger than the cross-section of the second chamber (9), the first chamber (8) is closed by a first piston (10) and the second chamber (9) is closed by the second piston, the first chamber (8) being separated from the second chamber (9), and the second piston comprises at least one flow channel (16) or the first chamber comprises at least one closable, axially oriented freeze-drying channel (34), and the second chamber (9) comprises at least one axially oriented flow channel (36), on the respective rear ends of the chambers (8, 9). The invention also relates to a method for filling the cylinder-piston unit (11). |
