| 摘要 |
Apparatus for metering one or more liquids comprising at least one tank (2) for the liquid to be metered, - a pipe (6, 6b) for drawing off the liquid to be metered from the tank, having an end nozzle (8) for delivery of the liquid to a storage container, - a recirculation pipe (10) communicating with the draw-off pipe (6, 6b) and with the tank (2) for recirculating to the tank the liquid to be metered, - reversible pumping means (18) associated with the draw-off pipe and able to operate in suction or compression mode, characterized in that it comprises non-return valve means (16a, 16b) associated with the recirculation pipe (10) and designed to close the recirculation pipe when the pumping means (18) are operated so as to draw off a metered quantity of the liquid from the tank and open the recirculation pipe, closing the draw-off pipe when the pumping means are operated in compression mode, and - shut-off valve means (24) communicating with the pumping means (18), with the delivery nozzle (8) and with the draw-off pipe and able to assume the position for performing closing in the direction of the delivery nozzle and for performing opening in the direction of the pumping means, so as to allow, when the pumping means are operated in suction mode, drawing off of a metered quantity of the liquid from the tank and, when the pumping means are operated in compression mode, selective recirculation of the liquid to the top of the tank, and able to assume the second position for performing opening in the direction of the delivery nozzle (8) and closing of the draw-off pipe so as to allow delivery of a metered quantity of the liquid into a storage container, when the pumping means are operated in compression mode. |
