Writing instrument

The writing instrument addresses dimensional variations by using a cover member and rotary drive mechanism to maintain aesthetic appeal and functional consistency.

WO2026089010A1PCT designated stage Publication Date: 2026-04-30MITSUBISHI PENCIL CO LTD
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Patent Information

Application Number
PCT/JP2025/037257
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-10-25
Filing Date
2025-10-23
Publication Date
2026-04-30

AI Technical Summary

Technical Problem

Writing instruments face issues with compromised aesthetic appeal due to variations in dimensions during manufacturing and changes in dimensions or shape over time, particularly when gripping members made from materials like wood or rubber elastic materials, leading to gaps and visibility of internal components.

Method used

A writing instrument design featuring a cover member that covers the outer surface of a receiving end of a cylindrical member without abutting in the axial direction, along with a chuck unit and rotary drive mechanism to manage the writing lead, ensuring the aesthetic appeal is maintained despite dimensional variations.

Benefits of technology

The design prevents the impairment of aesthetic appeal by covering dimensional variations and changes over time, while also managing the writing lead effectively.

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  • Figure JP2025037257_30042026_PF_FP_ABST
    Figure JP2025037257_30042026_PF_FP_ABST
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Abstract

A writing instrument (1) is provided with: a shaft tube (4); a tip member (6) which is provided with a reception end part having inserted therein the front-end part of the shaft tube (4), and which is attached to the shaft tube (4); a grip member (20) which is disposed on the outer surface of the shaft tube (4); and a cylindrical cover member (40) which is disposed on the outer surface of the shaft tube (4) while being in contact with one end part of the grip member (20). The cover member (40) is configured to cover the outer surface of the front-end part of the tip member (6) without being in contact with the tip member (6) in the axial direction.
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Citation Information

Patent Citations

  • Electromotive type mechanical pencil

    JP2008155381A

  • Writing utensil

    JP2017113992A

  • Mechanical pencil

    WO2022092293A1