Patent ID: 7828020

Claim:
A method of dispensing a liquid from a liquid dispenser comprising: providing a cartridge having; a hollow body for containing the liquid; an aperture defined in the hollow body; and an externally actuatable pumping device including: a dispensing tube which defines an interior surface connected to the hollow body at the aperture for dispensing the liquid from the hollow body; a valve seat, including a port for passing the liquid through the dispensing tube, connected to the dispensing tube and fixed within a space defined by the interior surface of the dispensing tube; a valve body in removable contact with the valve seat on a discharge side thereof which covers the port in a closed position and uncovers the port in an open position; and a piston located on an upstream side of the valve seat that is fixed to the valve body and is moveable within the dispensing tube for forcing the liquid through the port; inserting the cartridge in the liquid dispenser; and moving the piston from a first position, away from the valve seat, in which the valve body is closed, to a second position, toward the valve seat and in a direction of liquid flow.