Retractable Pen Ball Shutter with Projection Jaws for Sealing
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Solution Overview
Problem
Conventional retractable writing instruments with drying prevention units often experience issues with incomplete sealing of the nib, leading to ink drying out due to excessive pivoting of the ball-type door, resulting in defects.
Innovation Solution
The writing instrument features a ball shutter with fan-shaped hinge shafts and projection jaws on the holder to limit the pivot range, ensuring complete sealing and preventing ink smearing by maintaining the ball shutter on a straight line during closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the ball-type door is allowed to pivot freely to open the shaft, then the nib can protrude from the front opening, but the ball-type door may pivot excessively by exceeding 90 degrees, causing incomplete sealing and ink drying
Solution Approach 1:
The projection jaw is designed to preemptively stop the hinge shaft at the exact position where the ball-type door achieves complete sealing (90 degrees), preventing any further pivoting that would cause incomplete sealing. This preliminary anti-action counteracts the tendency of the hinge shaft to pivot excessively by providing a mechanical stop before the harmful effect occurs.
Solution Approach 2:
The projection jaw provides immediate mechanical feedback to the hinge shaft when the ball-type door reaches the correct sealing position. The contact between the projection jaw and hinge shaft creates a definitive stop signal that prevents over-pivoting, ensuring the sealing function is always completed properly before allowing any return motion.
2Ease of operation
If the ball-type door is designed to pivot by about 90 degrees to seal the front opening, then the nib can be retracted into the body case, but pivoting by exceeding 90 degrees causes the nib to not be tightly sealed
Solution Approach 1:
The projection jaw is positioned to preemptively prevent the hinge shaft from pivoting beyond the 90-degree mark. By providing a mechanical barrier before excessive pivoting can occur, the design ensures that the ball-type door always achieves complete sealing regardless of manufacturing tolerances or wear over time.
Solution Approach 2:
The projection jaw acts as a pre-positioned protective element that cushions against the potential harm of over-pivoting. By having this stop mechanism in place beforehand, the system is protected from sealing failures that would otherwise result from hinge shaft rotation exceeding the required 90 degrees.
3Adaptability or versatility
If the hinge shaft is allowed to pivot without restriction, then the ball shutter can open completely to allow nib protrusion, but excessive pivoting causes ink smearing on the nib
Solution Approach 1:
The projection jaw preemptively counteracts the harmful effect of excessive pivoting by providing a mechanical stop at the optimal sealing position. This prevents the ball shutter from opening too wide during retraction, which would cause the nib to contact the inner wall of the body case and smear ink.
Solution Approach 2:
The projection jaw converts the potential harm of unrestricted pivoting into a beneficial feature by using the hinge shaft's own rotational motion to trigger the stop mechanism. The excessive pivoting tendency is transformed into a self-regulating system where the hinge shaft naturally engages the projection jaw to achieve precise positioning.
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
This configuration effectively prevents ink from drying out by ensuring the nib is securely sealed, reducing defects associated with incomplete sealing and ink smearing.
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
AI summary
A writing instrument having an automatic sealing structure, in which a hinge part of a holder has projection jaws formed thereon having a role of a stopper that can prevent a hinge shaft from being excessively pivoted, thereby more effectively preventing ink from drying out due to complete sealing of the nib. The writing instrument having an automatic sealing structure, including: 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; and a ball shutter pivotally coupled to the holder to allow the nib to protrude or be sealed according to the pivoting thereof, wherein the ball shutter includes hinge shafts formed in a fan shape, and hinge parts of the holder, in which the hinge shaft is pivotally positioned, have projection jaws formed thereon by protruding inwardly to limit a pivot range of the hinge shaft.