GB1301183A - A liquid dose measuring and discharging device - Google Patents

Abstract

1301183 Raising and discharging liquids AIRAM AB OY 16 April 1970 [18 April 1969] 18305/70 Heading F1R A liquid dose measuring and discharging device in particularly for mercury, Fig.1 comprises a supporting tube 2 and a capillary tube 11 in which is movable a stem 5 to form at the bottom of the tube 11 an open ended chamber of variable volume, and which is connectable by a line 12 to an air pump 20, Fig. 4, to withdraw air from around the stem 5 and cause liquid to enter the tip only of the tube as further upward movement is prevented by the liquids surface tension, and subsequently to create a blowing action to discharge the liquid. The stem 5 which has a flattened portion (14), Fig. 3 (not shown) to assist withdrawal of air passes through a stuffing box 9 and is axially adjustable to enable different dose volumes to be selected. The air pump 20 comprises a flexible tube 24 connected to a mercury reservoir (not shown), which moves together with a slide 21 under the action of a counterweight 22. During downward movement of the slide 21 a spring-loaded switching tongue 27 causes a mechanism 19 to pivot to bring a mercury storage container 18 under the capillary tube and creates a vacuum in the line 12 so drawing mercury into the tube 11. Upward movement of the slide 21 causes a momentary pressure increase in the line 12 to discharge a droplet of mercury.