Writing instrument with self-closure

Claim 1

A writing instrument having a barrel, a writing tip disposed in said barrel, a retracting mechanism for said writing tip, and a self-closure operatively associated with said barrel and said writing tip; said closure comprising a plurality of resilient segment members having tapered lower end portions, said lower end portions being complemental with each other when said segment members are operatively disposed so as to define a hollow protective enclosure for said writing tip, and closure-actuating means interconnecting said barrel and said segment members for moving said segment members in relation to said barrel between a first position in which said segment members are operatively disposed and another position in which said segment members are retracted so as to permit exposure of said writing tip, said closure-actuating means comprising screw thread portions disposed in said barrel, screw thread portions on said segment members complemental with said first-mentioned screw thread portions, means interconnecting said barrel and said segment members for rotating said segment members with respect to said first-mentioned screw thread portions, whereby said segment members may be moved between said positions and said barrel comprising an upper portion remote from said writing tip and a lower portion adjacent said writing tip and rotatably coupled to said upper portion in coaxial alignment therewith, said screw thread portions in said barrel being disposed in said upper portion, and said means interconnecting said barrel and said segment members comprising interlock means between said lower portion and said segment members so that said segment members rotate with said lower portion upon rotation of said lower portion with respect to upper portion.