Method for positioning an ink cartridge, and the ink cartridge and ink jet recording apparatus used for such method

A method for positioning a cartridge by allowing the fitting portion of the ink cartridge to engage with the ink supply tube supporting portion of the ink cartridge housing when the ink cartridge is mounted on the ink cartridge housing includes the steps of positioning the ink supply tube and the ink cartridge fitting portion by guiding the ink cartridge by means of the engagement between the ink cartridge housing member and the ink cartridge until the fitting portion of the ink cartridge and the supporting portion of the ink supply tube begin to engage with each other; and completing the mounting of the ink cartridge on the ink cartridge housing member by loosening at least partly the engagement between the ink cartridge housing member and the ink cartridge after the engagement is made between the fitting portion of the ink cartridge and the supporting portion of the ink supply tube. With such structure, the operativity of the method is enhanced, while positioning the supply tube and the fitting portion of the ink cartridge in high precision. Further, no load is given to the supply tube and the supply tube supporting portion after the completion of its engagement.