Deformable Mandrel Head Blind Rivet for Dissimilar Apertures
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Solution Overview
Problem
Conventional blind rivets face difficulties in reliably joining materials with dissimilarly sized apertures, requiring costly adjustments to match aperture sizes, which complicates and increases manufacturing costs.
Innovation Solution
A blind rivet with a deformable mandrel head, particularly having a tapering cross-section and ribbed surfaces, allows for secure attachment of materials with different aperture sizes by evenly deforming around the apertures and minimizing rotation through engagement with the aperture edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional blind rivets are used to join materials with dissimilar aperture sizes, then the joining process is simplified, but the rivet cannot reliably engage the inner surface of wider apertures allowing transverse movement
Solution Approach 1:
The mandrel head is designed to be deformable rather than rigid, allowing it to dynamically adapt its shape during the setting process. When the mandrel is pulled, the mandrel head deforms to conform to the specific aperture geometry, enabling reliable engagement whether the aperture is narrow or wide. This dynamic deformation capability resolves the contradiction by allowing a single rivet design to adapt to varying aperture conditions.
Solution Approach 2:
The mandrel head undergoes parameter changes in its physical state during installation. It transitions from an undeformed state with a larger cross-section to a deformed state where it conforms to the aperture dimensions. This parameter change allows the mandrel head to adjust its engagement characteristics based on the specific aperture size, resolving the contradiction between adaptability and reliable engagement.
2Reliability
If aperture sizes are matched across all materials, then reliable rivet engagement is achieved, but manufacturing complexity and cost increase due to additional drilling operations
Solution Approach 1:
The blind rivet with deformable mandrel head is designed to perform multiple functions: it can reliably engage both narrow and wide apertures without requiring pre-matching of aperture sizes. This universal capability eliminates the need for additional drilling operations to match aperture dimensions, resolving the contradiction by providing reliable engagement while maintaining manufacturing simplicity.
Solution Approach 2:
The deformable mandrel head performs self-adjustment during the setting process, automatically adapting to the specific aperture dimensions without requiring external intervention or pre-processing. This self-service capability allows the rivet to achieve reliable engagement on its own, eliminating the need for complex manufacturing processes to match aperture sizes.
3Device complexity
If a rigid mandrel head is used, then the structure is simpler, but the rivet body portion cannot be evenly deformed around the aperture
Solution Approach 1:
The mandrel head transitions from a rigid structure to a deformable one, allowing it to dynamically adjust during the setting process. This deformability enables the mandrel head to apply force evenly to the rivet body portion as it deforms, ensuring uniform engagement around the aperture. The dynamic nature of the mandrel head resolves the contradiction by providing both structural simplicity and deformation control.
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
Enables reliable joining of materials with dissimilar apertures without the need for costly adjustments, ensuring secure fastening and preventing relative movement or rotation between joined pieces, while maintaining electrical continuity if necessary.
Implementation Method 1
the force F1 applied to the mandrel stem 108 causes the mandrel head 110 to exert a force on the rivet body portion 104 of the blind rivet 100. Such a force causes deformation of the rivet body portion 104 as the mandrel head 110 is pulled towards the pieces of material 102 being joined together
Implementation Method 2
said mandrel head has a plurality of ribs arranged on an outer surface thereof for engaging an aperture in a work piece. This increases the grip of the rivet on the work piece thereby providing the advantage of minimizing rotation of the work piece relative to the rivet
Data Source
Figure 1a~1d
Figure 2
Figure 3a~3d
AI summary
A blind rivet 200 comprises a mandrel 214 having a deformable mandrel head 218 such that when the blind rivet is received in a pair of aligned apertures of dissimilar sizes in a pair of components 220, 222 to be joined, the mandrel head is adapted to be deformed and cause deformation of a rivet body 202 such that the blind rivet engages the inner surfaces defined by both of the apertures before the mandrel and its head are pulled free of the rivet body.