Writing Instrument Ink Cartridge Plug Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional writing instruments with replaceable ink cartridges often experience ink leakage when the used cartridge is pulled out, due to the movement of the plug and its potential collision with the container bottom, leading to deformation or disengagement, and noise issues.
Innovation Solution
A writing instrument design where the plug is fitted between a projection and the container's inner surface, with a tapered shape and ink intake portions, allowing secure fitting and movement control to prevent ink leakage, using male and female fitting portions for secure attachment and detachment, and a stepped portion to restrict plug movement, ensuring ink is locked in place during replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the plug is freely movable in the plug opening state, then the plug can be easily pressed open by the projection, but the plug makes contact with the container inner wall every time it moves to produce noise and may collide with the connection portion or bottom wall causing deformation or disengagement
Solution Approach 1:
The patent applies preliminary action by providing a guide groove in the container inner wall that pre-defines the movement path of the plug. This guide groove is formed beforehand to guide the plug during its movement from the closed to open state, preventing arbitrary contact with the container wall and reducing noise while maintaining ease of opening.
2Reliability
If the plug is restricted in movement range, then ink leakage is reduced, but the plug cannot be easily pressed open and may require excessive force
Solution Approach 1:
The guide groove is pre-formed in the container inner wall to establish a controlled movement path for the plug. This preliminary structural arrangement allows the plug to move smoothly along the groove while maintaining restricted movement range, preventing ink leakage without requiring excessive force for opening.
3Ease of operation
If the plug is freely movable during cartridge replacement, then the cartridge can be easily removed, but ink leakage occurs when the container is pulled out at certain speeds and orientations
Solution Approach 1:
The guide groove is pre-formed to control plug movement throughout the cartridge replacement process. When the cartridge is removed, the plug follows the guide groove path and automatically returns to the closed position, ensuring ink leakage suppression while maintaining easy cartridge replaceability.
4Ease of manufacture
If the plug structure is simple, then manufacturing is easier, but the plug cannot be securely locked and moved back into position during replacement
Solution Approach 1:
The guide groove is pre-formed in the container inner wall to provide automatic positioning for the plug. This preliminary structural feature ensures the plug is securely locked and moved back into position during replacement without requiring complex plug structures, maintaining manufacturing simplicity while improving positioning accuracy.
Data Source
Figure 1~3
Figure 4(a)~4(c)
Figure 5(a)~5(b)
AI summary
Provided is a writing instrument, having high cartridge replaceability and excellent convenience, that is capable of suppressing inappropriate ink leakage that easily occurs when a used cartridge container is pulled out even when the writing instrument uses a replacement ink cartridge with a plug to be press opened. A writing instrument includes: a replacement ink cartridge including a bottomed cylindrical container that has an opened front end and a closed rear end and a plug fitted into an inner circumferential surface of an opening of the container; and a projection inserted into the opening of the container to press the plug rearward, thereby opening the plug of the ink cartridge, wherein the projection and the plug are fitted when the plug is press opened, and when the cartridge is replaced, the fitting between the projection and the plug is released and the plug is locked again in the opening of the container.