Patent ID: 6932794

Claim:
A medication delivery pen for expelling medication from a medicine cartridge, said pen comprising: a driver; a dosing ring non-rotatably disposed on said driver and axially slidable thereon and therealong; and, a dose knob coaxially disposed about said dosing ring, wherein at least one tooth is formed on one of said dose knob and said dosing ring, and wherein at least one groove is formed on the other of said dose knob and said dosing ring, said tooth and said groove being formed for selective cooperative engagement with each other; wherein said dosing ring is selectively movable axially relative to said dose knob from a first position where said tooth and said groove are spaced apart from each other, to a second position where said tooth and said groove are cooperatively engaged with each other such that said dosing ring is rotatable with said dose knob when said dosing ring is in said second position.