Patent ID: 7303267

Claim:
An ink cartridge refill system configured to refill an ink cartridge, the system comprising: an ink supply unit including a first portion and a second portion, wherein the first portion includes a plurality of ink tanks; a drain conduit extending from the first portion of the ink container to the second portion of the ink container; a vent conduit extending from the first portion of the ink container to the second portion of the ink container, wherein the vent conduit and drain conduit are configured for simultaneous fluid flow and wherein the fluid flow in the drain conduit is configured to automatically stop when the fluid flow in the vent conduit is stopped; and a pressure varying means configured to alter a pressure condition in the internal ink tank of the ink supply unit to generate ink flow in the drain conduit, wherein the pressure varying means is operatively mounted to the ink tanks and includes a pliable portion of a wall of the ink supply unit.