GB1250451A - - Google Patents

Abstract

1,250,451. Dispensing measured quantities of liquids. BASS CHARRINGTON Ltd. 14 Oct., 1968 [15 July, 1967], No. 32651/67. Heading B8N. Apparatus for dispensing measured quantities of liquid comprises a small bore tube having an internal diameter in the range 1/16 to 1 inch, a free piston member movable along the tube between predetermined limit positions, limit means which serves to prevent movement of the piston member beyond the limit positions, and valve means for connecting one end of the tube alternately to a liquid inlet and an outlet and for allowing, in use, fluid to be supplied to the other end of the tube when the one end is connected to the outlet. In the embodiment of Fig. 1, the piston member 12 is a capsule of P.T.F.E. containing air or gas, and valves 14, 16 connect inlet 18 to one of the ends of the tube 10 and simultaneously connect the other end to a delivery conduit 20. The valves are actuated directly by manual operation of a tap or indirectly by means of a switch which controls an electric solenoid or solenoids. A detent device is associated with the valves so that once a dispensing operation has commenced the apparatus cannot be stopped or reversed until a full measure has been dispensed. The detent device may be combined with a counting device to indicate the number of measures dispensed. Members 22 constitute the limit means. In the embodiment of Fig. 2 the limit means includes switches 48, 50 actuated by piston member 12 which contains a small amount of ferrous metal. Initially valves 54, 56 are open and valves 58, 52 are closed. Manual opening of tap valve 62 allows liquid to flow via valve 54 and displace the piston member. A measure of liquid is thus discharged via valves 56 and 62. When switch 48 is actuated the valves 52, 54, 56, 58 are reversed and valve 62 is automatically closed. A further measure will be dispensed when the valve 62 is again manually opened. Switches 48, 50 have "hold-in" devices associated therewith such that, once activated, they are not deactivated until a full measure has been dispensed. In a further embodiment (Fig. 3, not shown) similar in operation to that of Fig. 2 two small bore tubes are connected together. Each tube contains a piston member and the space between those members is filled with air.