Flexible Chalk Box Tip for Secure Line Holding
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Solution Overview
Problem
Existing chalk boxes lack a secure mechanism to hold the line at the exit hole, leading to inaccuracy and chalk spillage, and users often get chalk on their hands during use.
Innovation Solution
A chalk box with a housing containing a spool and a flexible tip with gripping fingers that can be squeezed to hold the line securely, reducing chalk transfer to the user's hands and minimizing spillage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the line is held manually at the exit hole without a securing mechanism, then the device structure remains simple, but chalk spillage occurs and line positioning accuracy deteriorates
Solution Approach 1:
The patent employs a flexible lip made of elastomeric material at the exit opening that can be squeezed by the user's thumb to open and release the line, then automatically returns to its original closed position to secure the line and prevent chalk spillage. This flexible component provides an effective sealing and holding mechanism without adding complex mechanical structures.
2Measurement precision
If the user holds the line near the chalk box for alignment, then alignment visibility is improved, but chalk transfers to the user's hands
Solution Approach 1:
The flexible lip acts as an intermediary between the user's hand and the line/chalk system. By providing a dedicated gripping point at the exit opening, it allows the user to hold the line without direct contact with chalk, thus maintaining alignment accuracy while preventing chalk transfer to the hands.
Solution Approach 2:
The flexible lip extracts the line-holding function from the user's fingers and concentrates it at a specific location (the exit opening), allowing the user to grip the line cleanly without chalk contamination while maintaining proper alignment visibility.
3Ease of operation
If the exit opening remains open for line access, then line retrieval is easy, but chalk spills out of the box
Solution Approach 1:
The flexible lip provides a dynamic opening mechanism that transitions between closed (securing chalk) and open (allowing line retrieval) states. The user squeezes the lip with their thumb to temporarily open it for line access, and when released, it automatically closes to prevent chalk spillage, thus resolving the contradiction between ease of operation and chalk loss.
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 ensures accurate chalk lines and reduces chalk spillage by securely gripping the line at the exit, maintaining precision and cleanliness.
Implementation Method 1
The flexible tip is adapted to be squeezed to reduce the diameter of the hole
Implementation Method 2
The facing surfaces can include serrations to grip the line
Data Source
AI summary
A chalk box having a housing that includes a spool mounted within the housing for rotation with respect to the housing. A line is wound upon the spool and a crank is mounted to the spool to rotate the spool with respect to the housing. The housing has an exit opening and a flexible tip mounted adjacent the opening. The flexible tip has a hole in communication with the exit opening. The flexible tip is adapted to be squeezed to reduce the diameter of the hole. The flexible tip is adapted to hold the line when the flexible tip is squeezed. The line can be retracted into the housing when the crank is turned and the spool is rotated.