Patent Number: 7,101,102

Title: Capless writing instrument

Abstract: A capless writing instrument (1), wherein a writing element (5) is arranged inside a barrel cylinder (2) so that a pen point (6) of the writing element (5) can come out and retract through a front end opening of the barrel cylinder (2), is characterized in that an inner cap (20) formed of rubber or elastic resin is provided at the front end opening of the barrel cylinder (2), and the inner cap (20) is composed of: a closing portion (21) disposed on the pen point projecting side with respect to the axial direction of the barrel cylinder for closing the front end opening and having a slit (25) for allowing the pen point (6) to project and retract; and forward projected portions (27) that are projected from the outer periphery of the closing portion (21) toward the front end opening, and the inner cap is fitted inside the barrel cylinder so that, in the slit (25) closed state, force which is directed approximately perpendicular to the slit surfaces will act inward from the outer periphery of the forward projected portions (27).

Inventors: Sawa; Yukinori (Fujioka, JP)

Assignee: Mitsubishi Pencil Co., Ltd.

International Classification: B43K 5/16 (20060101)

Expiration Date: 9/05/02018