DOSE DIAL AND DRIVE MECHANISM SUITABLE FOR USE IN DRUG DELIVERY DEVICES.

摘要

The invention relates to a dose dial and drive mechanism for use in a drug delivery device comprising a housing (2); a dose dial sleeve (50); a piston rod (10); a drive sleeve (26) is threadedly connected to the said piston rod (10); a reset sleeve (30), which is located between said drive sleeve (26) and said housing (2); and a dose display. When said dose dial sleeve travels towards the second end of said housing the reset sleeve is carried with said dose dial sleeve towards the second end of said housing resetting said dose display to a zero position; and when said dose dial and/or the reset sleeve travels towards the first end of said housing, the said dose dial sleeve and/or reset sleeve engage(s) with said drive sleeve thus advancing both said drive sleeve and said piston rod towards the first end of said housing.