Pen nibs and fountain pens
The pen nib's innovative passage structure in fountain pens reduces ink leakage and squirting by using alternating front wall portions to manage ink flow, addressing the impact-related issues in double-nib structures.
JP2026061898APending Publication Date: 2026-04-09PILOT PEN CO LTD
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2026-04-09
AI Technical Summary
Technical Problem
Fountain pens with a double-nib structure face issues with ink leakage and squirting from the air passage, particularly when subjected to impact, especially when the nib points downwards.
Method used
The pen nib features an ink passage with a first and second slit, an outer core with a through hole, and an inner core with a rear groove and front passage, including alternating front wall portions that reduce ink momentum and increase resistance, preventing ink from spilling.
Benefits of technology
The design effectively suppresses ink from spilling out of the air passage, even under impact, by reducing ink momentum and increasing resistance through a complex passage structure.
✦ Generated by Eureka AI based on patent content.
Smart Images
Figure 2026061898000001_ABST
Abstract
This suppresses ink leakage from the air passage in the pen nib. [Solution] The pen core 30 comprises an ink passage 32 through which ink 80 flows from the ink reservoir 16 to the pen tip 22 when writing, an air passage 34 through which air flows from the outside to the ink reservoir, an outer core 40 having a through hole 42 extending in the axial direction da, and an inner core 50 disposed within the through hole. The outer core has a first slit 44 that connects the through hole to the outer peripheral surface 46 of the outer core. The inner core has a second slit 52 that extends in the axial direction and communicates with the first slit, a rear groove 54 that extends in the axial direction, a wall portion 63 located in front of the rear groove, a plane 67 that is circumferentially offset from the rear groove and extends parallel to the central axis A, and a front passage 70 located in front of the wall portion that bends along the plane and extends forward. The ink passage includes the first slit and the second slit, and the air passage includes the rear groove, the wall portion and the front passage.
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Citation Information
Patent Citations
Fountain pen having double pen core structure
JP2017213767A