Blind Tacking Fastener With Fracturing Stem Head for Clean Removal
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Solution Overview
Problem
Temporary fasteners used in manufacturing often cause damage to workpieces during removal, such as scratching or chip formation, which can lead to complications during the installation of permanent fasteners.
Innovation Solution
A blind tacking fastener system comprising a stem and sleeve, where the stem head fractures from the body under pulling force, allowing for embedding or detachment within the sleeve, and featuring a bulb and serrated portion for secure alignment and easy removal, reducing damage by minimizing large chip formation during drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If temporary fasteners are removed by drilling, then the fasteners can be easily removed, but chips break off and cause damage to workpieces or bind drill bits
Solution Approach 1:
The stem is segmented into a body and a head that can separate from each other. During removal, the head fractures off from the body, allowing the smaller body to be drilled out without the head interfering and causing chip binding issues
Solution Approach 2:
The head is extracted or separated from the stem body during the removal process. This extraction eliminates the problematic head portion that would otherwise create large chips and bind drill bits, while the remaining body can be cleanly removed
2Force
If temporary fasteners are designed to provide strong sheet takeup capability, then workpieces can be pulled together effectively, but the fastener strength requirements increase
Solution Approach 1:
The fastener transitions from a static single-piece structure to a dynamic two-part structure where the head can fracture off. This allows the fastener to provide strong holding force during installation while enabling easy removal without requiring excessive strength throughout the entire fastener
3Stability of the object's composition
If the stem head remains attached to the body during removal, then the fastener maintains its structural integrity, but large chips form and bind drill bits
Solution Approach 1:
The stem is designed with a fracture point that segments the head from the body during removal. This segmentation prevents the formation of large continuous chips that would bind drill bits, while maintaining structural integrity during the installation and holding phases
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 blind tacking fastener system effectively aligns workpieces, provides strong sheet takeup, and minimizes damage during removal, ensuring efficient fastening and installation of permanent fasteners while reducing the risk of scratching and chip-related issues.
Implementation Method 1
the stem comprises a first material and the sleeve comprises a second material selected such that stem head fractures from the body from a pulling force exerted on the gripping portion
Implementation Method 2
the stem comprises a first material and the sleeve comprises a second material selected such that stem head fractures from the body
Data Source
AI summary
A blind tacking rivet includes a stem and a sleeve. The stem includes a body and a stem head. The stem head is removable from the body. The stem head deforms a portion of the sleeve during removal of the stem head. The stem head may be discarded or may be embedded within the sleeve.