Dual-Tip Writing Implement with Elastic Joint for Variable Line Width

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Solution Overview

Problem

Existing writing instruments, such as ballpoint pens, are limited in their ability to produce thick lines and are prone to damage and wear, while felt-tip pens and markers struggle to create lines with varying thickness and characteristics like 'stops' and 'sweeping strokes' effectively.

Innovation Solution

A writing implement with a shaft housing an ink supply core and a surrounding member, connected by an elastic joint that allows relative positional change, enabling the tip of the ink supply core and surrounding member to contact the writing surface simultaneously, allowing for variable line width and reduced wear through capillary ink flow and distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a ballpoint pen structure is used to enable variable line width, then the line width can be adjusted, but the line thickness is limited and cannot produce thick lines

Engineering Contradiction:
Improveline width adjustmentVSAvoidline thickness capability
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The writing implement is divided into multiple writing tips (first writing tip and second writing tip) with different line width capabilities. The first writing tip produces a first line width while the second writing tip produces a second line width greater than the first, allowing the user to switch between tip types to achieve both thin and thick lines as needed

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first writing tip and second writing tip are arranged coaxially and nested within the same holder, with the second writing tip having a larger outer diameter than the first writing tip's outer diameter. This nested arrangement allows both tips to be housed in a single instrument body while maintaining their respective writing functions

Inventive Principle:
Principle #7Nested doll (Nesting)

2Device complexity

If a single pen tip is used, then the structure is simple, but the pen tip is susceptible to damage and wear

Engineering Contradiction:
Improvetip structureVSAvoidtip durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

Different writing tips are designed with different local qualities suited to their specific functions. The first writing tip is optimized for producing thinner lines while the second writing tip is optimized for producing thicker lines. Each tip's material composition, surface treatment, and geometric features are tailored to its intended use, allowing both tips to exhibit high durability in their respective applications

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The writing implement provides dynamic adaptability by allowing the user to switch between different writing tips based on the writing task requirements. This dynamic configuration enables the system to optimize performance and durability for each specific writing condition rather than relying on a single static tip design

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If a felt-tip pen structure is used, then thick lines can be produced, but the ability to create lines with varying thickness and characteristics is limited

Engineering Contradiction:
Improveline thicknessVSAvoidline characteristic variation
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The felt-tip writing implement is segmented into multiple writing tips with different characteristics. The first writing tip is designed for producing thinner lines while the second writing tip is designed for producing thicker lines. This segmentation allows the implement to achieve both thick line capability and variable line width control that a single felt-tip cannot provide

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The writing implement achieves multi-functionality by incorporating multiple writing tips with different line width capabilities within a single instrument. The first writing tip handles thin line requirements while the second writing tip handles thick line requirements, making the implement universally capable of producing various line characteristics without requiring multiple separate instruments

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the drawing of lines of varying thickness and complex strokes with reduced wear and damage, providing a smooth writing experience by distributing writing pressure across the surrounding member and utilizing capillary action for ink flow.

Implementation Method 1

an ink supply core, such as that of a felt-tip pen or marker pen, that is housed inside the shaft, and that is capable of guiding ink by capillary force

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3165379B1Writing tool
Publication Date: 2021.09.29 MITSUBISHI PENCIL CO LTD
  • EP3165379B1 patent drawingFigure 1A~1B
  • EP3165379B1 patent drawingFigure 2
  • EP3165379B1 patent drawingFigure 3A~3C

AI summary

Lines can be freely varied in thickness, and lines with characteristics such as "stops", "flicks", and "sweeping strokes" can be written easily, even with a felt-tip pen, marker pen, or the like. Moreover, a pen-tip does not readily become damaged or worn. A writing implement includes a shaft, an ink supply core such as that of a felt-tip pen or a marker pen, and a core surrounding member that covers the ink supply core. The writing implement is formed capable of contacting a tip of the ink supply core and a tip of the core surrounding member against a writing surface at the same time by using a displacement means capable of changing a relative positional relationship between the ink supply core and the core surrounding member.