An inkjet print cartridge is described which has a first fill port, for initially filling the print cartridge with ink, and a refill port for recharging the print cartridge. The refill port includes a slideable valve which is engageable with a valve on an external ink reservoir to create an airtight...http://www.google.com.au/patents/US5777648?utm_source=gb-gplus-sharePatent US5777648 - Inkjet print cartridge having an ink fill port for initial filling and a recharge port with recloseable seal for recharging the print cartridge with ink 
