PISTON PUMP AND DRIVER THEREFOR

摘要

A pump driver, a disposable pump cartridge for use with the pump driver and a beverage dispenser employing the pump drive are disclosed. The disposable pump cartridge comprises at least one barrel 20 having an inlet valve 24 and an outlet valve 26 associated therewith. A piston 28 movable within the barrel 20 is retained in a minimum volume position during transit by a protrusion 22 on the internal surface of the barrel 20. The piston 20 has a piston shaft 28 with a hollow end arranged, in use, to releasably engage a piston driver to drive the piston 28 from its minimum volume position to an operative position, and to reciprocate the piston 28 within the barrel 20 in its operative position to draw fluid into and pump fluid from the barrel 20 via the inlet valve 24 and outlet valve 26 respectively. Methods of engaging, disengaging and changing the disposable pump cartridge are also disclosed.