Retractable Pen Automatic Sealing Structure
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Solution Overview
Problem
Conventional retractable writing instruments with drying prevention units often have increased diameters due to larger ball shutters, leading to poor grip feel and increased air infiltration, which can cause ink to dry out.
Innovation Solution
A writing instrument with an automatic sealing structure featuring a reduced-sized ball shutter, utilizing a link with cutaway pieces and elastic lugs to pivot the ball shutter, minimizing the instrument's diameter and reducing air infiltration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the ball shutter size is increased to accommodate the link mechanism, then the writing instrument can achieve retractable nib function, but the entire diameter of the instrument increases and grip feeling deteriorates
Solution Approach 1:
The link is designed with a hollow column structure that allows the ball shutter to pivot within the link's internal space rather than requiring the ball shutter to be larger. The cutaway piece creates a three-dimensional clearance zone that enables rotational movement without increasing the external diameter of the assembly.
Solution Approach 2:
The ball shutter is nested within the hollow column structure of the link, allowing the pivot mechanism to be contained within the existing external dimensions. The cutaway piece allows the ball shutter to rotate inside the link's hollow space, maintaining a compact overall size.
2Ease of operation
If the ball shutter size is increased to accommodate the link mechanism, then the writing instrument can achieve retractable nib function, but the weight of the instrument increases
Solution Approach 1:
The hollow column structure with cutaway piece creates internal three-dimensional space that allows the ball shutter to pivot without requiring additional external material, thereby avoiding weight increase while maintaining the retractable function.
Solution Approach 2:
Material is removed to create the hollow column structure and cutaway piece, extracting unnecessary material that would otherwise increase weight. This extraction creates the necessary pivot space without adding external dimensions or weight.
3Length of stationary object
If the instrument diameter is reduced to improve grip feeling, then the writing instrument becomes more compact, but the link mechanism cannot accommodate the ball shutter pivoting
Solution Approach 1:
The hollow column structure concentrates the pivot accommodation function in a specific local region (the hollow space created by the cutaway piece) rather than requiring the entire link to be larger. This localized quality change enables pivoting within compact dimensions.
Solution Approach 2:
The cutaway piece creates vertical clearance within the hollow column that allows the ball shutter to pivot in three-dimensional space without increasing the horizontal diameter of the instrument, enabling compact design with full pivoting 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
The solution achieves miniaturization, improving the grip feel and effectively preventing ink from drying out by reducing the instrument's diameter and minimizing air infiltration during opening and closing.
Implementation Method 1
a spring (50) installed within the shaft (10) so as to allow the cartridge (40) to return to its original position by an elastic restoring force thereof
Implementation Method 2
an O-ring (60) supported by the spring (50) and fixedly fitted in the shaft (10)
Data Source
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AI summary
The present invention has an object to provide a writing instrument having an automatic sealing structure that may reduce an entire diameter of the writing instrument due to a decrease in a size of a ball shutter, thus to improve grip feeling of a user. The writing instrument having an automatic sealing structure includes: a body case having a front opening formed in one end thereof; a knock part coupled to the other end of the body case so as to make a nib protrude from or be retracted into the front opening of the body case by a pushing operation thereof; a cartridge inserted into the body case together with a spring in a state in which the knock part and the nib are coupled to both ends thereof, respectively; at least one O-ring fixedly fitted in the body case; a holder fixedly fitted in the body case so that one end thereof is covered by the O-ring; a ball shutter pivotally coupled to the holder to allow the nib to protrude or be sealed according to the pivoting thereof; and a link which is slidably fitted in the holder, and has a cutaway piece formed by protruding a circumferential portion of a part of a hollow column end thereof to allow the ball shutter to be pivoted