Patent ID: 8448827

Claim:
A nozzle for dispensing a liquid, the nozzle comprising: a nozzle adapter having a cylindrical inner surface; a nozzle tip comprising an outer surface, an inner surface having a helical groove, and a top end rotatably coupled to the nozzle adapter cylindrical inner surface; and a plunger disposed within the nozzle tip, the plunger comprising a body having a cylindrical outer surface, a top end, a tapered lower end that mates with a bottom of the nozzle tip inner surface to form a liquid tight seal between the plunger and the nozzle tip when the nozzle is closed, and at least one projection along the body outer surface between the top end and the lower end keyed to fit within the helical groove of the nozzle tip, wherein the plunger and the nozzle tip are configured so that rotational motion of the nozzle tip causes axial motion of the plunger relative to the nozzle adapter without appreciable axial motion of the nozzle tip relative to the nozzle adapter; a nozzle drive comprising an inner surface attached to the outer surface of the nozzle tip; and a drive mechanism coupled to the nozzle drive and configured to open and close the nozzle.