Writing instrument for ink which tends to dry up - has button actuated retractable writing element moved through opening in casing

摘要

Pen for ink which tends to dry up comprises a writing element (1), and a closure element (2) at the lower end of which is a stopper (6). By pressing a button, the writing element can be moved out through the opening (3) and retracted, and the closure element can be advanced to close the opening from the inside and retracted far enough for the writing element to pass the stopper the next time the button is pressed. The dia. of the stopper is at least equal to that of the opening. Alternatively, the opening may be closed by several segments which are biased radially outwards and which move together to close the opening in the manner of a claw.