US Patent 7758270 Ink refill tool for a writing instrument

A tool facilitates the insertion and removal of an ink reservoir unit, such as a cartridge, from a chamber of a writing instrument. The chamber is located within a drum that is coupled to a nib of the writing instrument. The tool comprises a main section defining, at least in part, an internal cavity for receiving the nib. The tool is configurable in a closed state, in which the nib is positioned inside the cavity and the tool clutches a grip portion of the writing instrument that is rigidly coupled to the nib and the drum. The tool is further configurable in an open state in which the cavity is partially open, compared to when the tool is in the closed state, thereby facilitating safe placement of the nib inside the cavity.