Protected Prong File Fastener with Heat Shrink Sheath
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional paper fasteners with metal prongs suffer from sharp edges that shear papers and cause injuries, and alternative materials like plastic are either too elastic or too rigid, leading to failures and metal fatigue from repeated bending.
Innovation Solution
A protected pronged file fastener with a non-metallic heat-shrinkable sheath covering the prongs, which are tapered to reduce snagging and increase the bending radius, preventing paper shearing and injury while maintaining flexibility and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal prongs are used in conventional fasteners, then the fastener provides strong binding capability, but the sharp edges shear papers and cause injuries
Solution Approach 1:
A protective sheath made of flexible material is introduced as an intermediary layer between the metal prong and the paper/documents. This sheath covers the sharp edges while allowing the prong to maintain its binding function, thus eliminating the harmful effects without sacrificing strength
Solution Approach 2:
The patent applies a flexible protective sheath (such as heat-shrinkable tubing or flexible coating) over the metal prongs. This thin film or shell covers the sharp edges, providing a safe surface while the underlying metal prong structure maintains the necessary binding strength
2Object-affected harmful factors
If plastic prongs are used to eliminate sharp edges, then safety is improved, but the plastic is either too elastic or too rigid causing cracks and failures
Solution Approach 1:
The patent creates a composite structure combining metal prongs with a flexible protective sheath. The metal provides structural strength and rigidity to prevent cracking, while the flexible outer layer provides safety by eliminating sharp edges. This composite approach achieves both reliability and safety simultaneously
Solution Approach 2:
By applying a flexible protective sheath over the metal prong, the patent achieves the safety benefits of a non-metallic surface while the underlying metal structure provides the reliability and crack resistance that pure plastic cannot achieve
3Adaptability or versatility
If the prongs are made bendable to adapt to document thickness, then adaptability is improved, but repeated bending causes metal fatigue
Solution Approach 1:
The protective sheath acts as a flexible outer layer that allows the prong to bend and adapt to different document thicknesses while distributing the stress. This flexible coating prevents stress concentration at the metal surface, reducing metal fatigue from repeated bending cycles
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 effectively prevents paper shearing, injuries, and metal fatigue by covering the prongs with a flexible sheath, ensuring secure document binding without sharp edges and maintaining the compactness and adaptability of traditional pronged fasteners.
Implementation Method 1
a non-metallic sheath overcoating covering a substantial portion of each prong
Data Source
AI summary
A prong style file fastener and the method of manufacture is disclosed which has a protective element to prevent damage to paper documents and personal injury. In one embodiment, the prongs of the fastener are covered with a heat shrinkable sheath. In another, the prongs are overcoated with a powder coating which is melted thereon. A method of applying the sheath to the prongs uses a pair of jaws or V-shaped surface to drive the sheath onto the prongs.