摘要 |
A medicament delivery device (1) comprises a housing (15), a telescopic piston rod assembly (12) for driving a bung (20) of a medicament container (9), and a drive mechanism (17) for the telescopic piston rod assembly. The telescopic piston rod assembly (12) comprises a plunger (35) for driving a bung (20), a key (40) for allowing predominantly axial movement between the plunger and the housing (30) and an input drive (18) telescopically coupled to the plunger and supported for rotational and axial movement relative the housing. The drive mechanism (17) additionally comprises a transfer drive (16) that operates to rotate the input drive (18). As the input drive (18) rotates, it moves axially relative to the housing (15), expanding telescopically relative to the plunger (35). |