Auto-Injector with gearbox

摘要

The invention relates to a gearbox for converting a first translation into a second translation, the gearbox comprising a drive collar connectable to a translative drive means and prevented from rotating with respect to a ground of the drive means, a drive sleeve rotatably arranged at least partially inside the drive collar, engaged to the drive collar by a first screw thread and prevented from translating, wherein a plunger is arranged at least partially inside the drive sleeve, engaged to the drive sleeve by a second screw thread and prevented from rotating.