Interchangeable nib for felt tip pen - has coiled wire holder in spiral about nib with L-shape fixing recess

摘要

The felt-tip pen has an interchangeable nib, the latter being changed from the forward end. The nib can have a holder wire coiled round it in a spiral, and situated on the sleeve portion. There can be an L-shaped recess cut in the nib. The pen can be refilled by replacement cartridges containing ink, these having screw threads with notches and pins at the end of the thread to lock them in place. Alternatively they can be secured by a bayonet coupling, or a protruding edge on the cylindrical portion of the nib.