Patent ID: 6713021
Filing Date: 2004-03-30
Classification: B01L,B05B,B05C,Y10T

Abstract:
A dispenser for discrete droplets of less than ten microliters (10 &mgr;l) in volume of a liquid comprising:(A) a main assembly; (B) a liquid container comprising: an elongated body member having a straight main bore; an inlet to the main bore; a valve seat in the body member forming a main bore outlet remote from and substantially in line with the inlet; a nozzle mounted on the body member and having a nozzle bore communicating with the valve seat; a droplet dispensing tip on the nozzle remote from the valve seat; a separate floating valve boss of magnetic material loosely mounted in the main bore, its cross-sectional area relative to that of the main bore being such as to permit the free flow of liquid between the main bore inlet and outlet by passing the valve boss, said valve boss not being mechanically connected to the body member; (C) means for releasably securing the liquid container to the main assembly; (D) means for exerting a pressure differential on the liquid in the dispenser; and (E) a separate valve boss actuating assembly adjacent the body member for applying an electromagnetic force to the valve boss to engage and disengage the valve boss from the valve seat.