Ballpoint Pen Variable Line Width via Rotating Ball
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Solution Overview
Problem
Conventional ballpoint pens with mechanisms to change line widths either have complex structures, ink leakage issues, or limited adjustability, making it difficult to draw lines of varying widths smoothly and consistently.
Innovation Solution
A ballpoint pen design featuring a writing ball, holder, ink supply, and an outer member that allows the writing ball to rotate within a ball house, enabling line width adjustment by changing the contact state with the writing surface through inclination and load application, maintaining optimal positional relations and minimizing ink leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a pressurizing mechanism is provided in the writing instrument to control ink leakage, then the width and thickness of drawn lines can be changed, but the structure becomes complex and it is difficult to adjust the pressing force during writing
Solution Approach 1:
The invention extracts the pressurizing mechanism from the writing instrument and replaces it with a simple elastic member (spring) that provides constant biasing force. The ink leakage control is achieved through the interaction between the writing ball rotation and the holder's narrowed portion, eliminating the need for complex active pressurization systems while maintaining line width variability.
Solution Approach 2:
The writing ball itself serves the dual function of transferring ink and controlling line width through its rotation within the holder. The elastic member automatically adjusts to writing pressure, providing self-regulating ink flow control without requiring external actuation or complex mechanisms.
2Adaptability or versatility
If only two types of pen tips are used to change line widths, then it is possible to draw bold and narrow lines, but it is not possible to continuously adjust the width of drawn lines and the writing shaft must be inverted
Solution Approach 1:
The invention transforms the static, discrete line width control (two fixed pen tips) into a dynamic, continuous control system. The writing ball can rotate freely within the holder to any angle, allowing continuous adjustment of the exposed portion and thus continuous variation of line width without changing tips or inverting the shaft.
Solution Approach 2:
A single writing ball serves multiple functions: it transfers ink, controls line width through rotation, and eliminates the need for multiple pen tips or shaft inversion. The holder's narrowed portion universally constrains the writing ball while allowing rotational movement, providing a unified solution for variable line width control.
3Adaptability or versatility
If the gap between the writing ball and narrowed portion is changed to control ink leakage, then the width and thickness of drawn lines change, but the movable distance of the writing ball is limited and large amounts of ink leak when the distance is increased
Solution Approach 1:
The invention changes the control parameter from vertical displacement distance to rotational angle. The writing ball rotates within the holder, changing the angular position and thus the exposed portion of the writing ball. This parameter change allows continuous line width adjustment without increasing the risk of uncontrolled ink leakage, as the elastic member maintains consistent biasing force throughout the rotation range.
4Ease of operation
If lines are drawn using the surface of a component, then it is difficult to provide smooth writing performance, but replacing with a writing ball may cause ink to not reach the marking surface portion
Solution Approach 1:
The writing ball acts as an intermediary between the ink supply and the marking surface. It rotates within the holder, allowing ink to be picked up from the ink supply and transferred to the marking surface through capillary action and surface tension. The holder's narrowed portion and elastic member work together to ensure the writing ball maintains optimal contact with the marking surface while preventing uncontrolled ink leakage.
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 different widths using a single writing tip, improving expressive power with smooth, high-quality strokes like 'stop,' 'hook,' and 'fade' while maintaining consistent ink supply and preventing blurring.
Implementation Method 1
The writing ball and an outer member tip end portion form a writing portion... enabling the drawing of lines of different widths using a single writing tip... maintaining optimal positional relations and minimizing ink leakage
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3
AI summary
Provided is a ballpoint pen having a simple structure and which is capable of writing lines having different widths, using one writing tip and without using any particular operation during writing. Also provided is a ballpoint pen capable of writing lines having different widths, with a single writing ball by using two writing portions. An outer member (50) covering the outer circumference of a holder (21) covers a section that reaches as far as a narrowed section (23) of the holder (21) and has an outer member tip end portion (51) capable of coming in contact with a writing surface at the same time that the writing ball (30) does. An ink is used that is capable of spreading between the writing ball (30) and the contact section of the writing surface and between the outer member tip end portion (51) and the contact section of the writing surface, in a state in which the writing ball (30) and the outer member tip end portion (51) are in contact with the writing surface at the same time. In addition, the relative position of the outer member (50) and the holder (21) can be changed to a holder retracted position and a holder protruding position. When the relative position is in the holder retracted position, the writing ball (30) and the tip section of the outer member (50) can be in contact with the writing surface at the same time.