Dispenser

摘要

A dispenser for a solid or soft solid mass has a barrel, a piston within the barrel, and a mechanism for advancing the piston axially within the barrel including a rotor wheel. A boss having an inwardly tapered profile (tear drop) and a sump dimensioned to receive the boss seats the rotor wheel at a predetermined angular position relative to the barrel. The boss is preferably formed on the rotor wheel and the sump in the base of the barrel. The dispenser is provided with a pair of bosses and sumps, symmetrically arranged around the rotor wheel and barrel base.