| 摘要 |
<p>An injection system for preparing a mixture of a solvent and a medicament and for subsequent dosed injection of the mixture comprises a syringe accommodating an ampoule (7) in which a liquid is stored between a membrane (8) dosing one end of the ampoule (7) and a piston (6) which can by a piston rod (3) be forced into the ampoule (7) to press out a dose of the liquid. The piston rod (3) and the piston (6) has mutual engaging threads (4, 5) by which the piston (6) is coupled to the piston rod (3) to follow this rod in both axial directions. An outer thread (30) engaging an inner thread (29) in a housing is provided on a part (28) of the piston rod (3) so that rotation of the piston rod (3) will screw this rod and the piston (6) into the ampoule (7). A detent (18) ensures that the piston rod (3) is only rotated in a dose administering direction. However, the thread (30) of the piston rod (3) can be disengaged from the thread (29) of the housing to set the piston rod (3) free to be moved in a proximal direction.</p> |
