Radial Pen Nib Structure for Quiet, Interference-Free Color Switching

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Solution Overview

Problem

Conventional multicolor ballpoint pens with knock or rotary mechanisms are cumbersome to operate, generate noise, and suffer from nib interference due to parallel nibs and close spacing, making them difficult to use for frequent color changes and writing.

Innovation Solution

A pen structure with pen nibs oriented outward along the axis centerline, allowing easy color switching by rotation and preventing nib interference through angled placement, and optionally including a stylus tip and eraser for convenience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a knock mechanism is used to switch colors, then color switching is enabled, but the pen barrel becomes thick and operation becomes cumbersome

Engineering Contradiction:
Improvecolor switching capabilityVSAvoidoperation convenience
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The invention extracts and removes the knock mechanism from the pen structure, eliminating the need for knocking to switch colors. The nibs are directly exposed at the tip of the pen barrel, allowing users to switch between colors by simply rotating the pen without any additional mechanical components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of hiding the nibs inside the pen barrel and requiring a knock mechanism to expose them, the invention inverts the approach by directly exposing the nibs at the tip. The selection mechanism is inverted from linear (knocking) to rotational (rotating the pen body), making operation more intuitive and convenient.

Inventive Principle:
Principle #13The other way round (Inversion)

2Adaptability or versatility

If parallel pen barrels are arranged close together, then multiple nibs are exposed, but nib interference occurs during writing

Engineering Contradiction:
Improvemultiple nibs exposureVSAvoidnib interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention transitions from a two-dimensional parallel arrangement of nibs to a three-dimensional radial arrangement. The nibs are positioned at different angular positions around the pen axis, extending outward in different directions rather than parallel to each other, which eliminates interference during writing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The nibs are arranged asymmetrically around the pen axis with different angular positions, rather than symmetrically parallel. This asymmetric radial arrangement ensures that when one nib is in use, other nibs are positioned at angles that prevent contact or interference with the writing surface.

Inventive Principle:
Principle #4Asymmetry

3Object-generated harmful factors

If a knock mechanism with rubbers is used, then noise is reduced, but switching time is still time-consuming

Engineering Contradiction:
Improveswitching noiseVSAvoidcolor switching time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The invention removes the knock mechanism and associated rubber dampers entirely. Without the knock mechanism, there is no switching noise to dampen, and the operational step of knocking is eliminated, directly reducing the time required to switch colors.

Inventive Principle:
Principle #2Taking out (Extraction)

4Volume of moving object

If nibs are hidden behind the body, then the pen structure is compact, but nib visibility is poor during writing

Engineering Contradiction:
Improvepen compactnessVSAvoidnib visibility
Core Design Contradiction:
Volume of moving objectVSDifficulty of detecting and measuring

Solution Approach 1:

The nibs are pre-positioned in an exposed state at the tip of the pen barrel, ready for immediate use. This preliminary exposure eliminates the need to knock or manipulate any mechanism to reveal the nibs, and the radial arrangement ensures that the selected nib is clearly visible and accessible from the start.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4588687A1Pen structure, ball-point pen, and touch pen
Publication Date: 2025.07.23 MARUYAMA NOBUTAKA
  • EP4588687A1 patent drawingFigure 1~3
  • EP4588687A1 patent drawingFigure 4(a)~6
  • EP4588687A1 patent drawingFigure 7(a)~8(c)

AI summary

To provide a pen structure that is easy to operate for switching colors and functions, and easy to write without interference when writing. The pen structure S has a pen barrel 10 to be held by hand, and a plurality of pen nibs 11a-11c disposed at one end of the pen barrel 10, which are oriented to open outward from a direction along the axis center line of the pen barrel 10. Further, it is preferred to further provide one or more nibs 12 and erasers 13, which are disposed at the other end of the pen barrel 10.