Flush Rivet with Swaged Lock Ring for Aerospace Fastening
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Solution Overview
Problem
Existing rivets used in aerospace and other industries face challenges in securely fastening work pieces with a flush installation and reliable locking mechanism, particularly in applications requiring high strength and durability.
Innovation Solution
A rivet design featuring a pin member with a lock groove, frangible portion, and a lock ring that is swaged into the lock groove to form a bead, allowing for secure engagement and flush installation, with the frangible portion breaking off to expose a surface for alignment, and a countersink head for flush surface integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional rivet design is used, then the structure is simple, but the locking reliability and flush installation quality are insufficient
Solution Approach 1:
The rivet is divided into distinct functional segments: a pin member with specific groove features, a separate lock ring component, and a frangible portion. This segmentation allows each component to perform its specific function optimally while maintaining overall reliability without excessive complexity.
Solution Approach 2:
The lock ring is nested within the pin member structure, with the lock ring positioned inside the hollow portion of the pin member. This nesting arrangement consolidates multiple locking functions into a compact integrated structure, improving reliability without significantly increasing external complexity.
2Strength
If a secure locking mechanism is implemented, then the fastening strength is improved, but the installation complexity increases
Solution Approach 1:
The lock ring is pre-positioned within the pin member during manufacturing, and the frangible portion is pre-configured to break at a specific point during installation. This preliminary preparation enables the strong locking mechanism to be installed easily through a simple pull action, without requiring complex installation procedures.
Solution Approach 2:
The frangible portion automatically breaks during the installation process when pulled, which triggers the lock ring to expand and engage with the work pieces. This self-actuating mechanism provides strong fastening without requiring additional manual operations or complex installation tools.
3Manufacturing precision
If a flush installation is achieved, then the surface quality is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The pin member features localized precision elements (grooves and frangible portion) only where needed for locking and alignment, while other portions maintain standard tolerances. This selective precision approach achieves the required surface alignment quality without demanding high precision throughout the entire manufacturing process.
Solution Approach 2:
The frangible portion is designed with specific dimensional parameters that cause it to break at a predetermined point during installation. This parameter control enables automatic alignment and flush surface achievement without requiring manual adjustment or post-installation machining, balancing precision requirements with manufacturing ease.
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 rivet provides a strong, flush, and secure fastening solution with double flush surfaces on opposite sides of the structure, enhancing durability and ease of installation, suitable for aerospace and industrial applications.
Implementation Method 1
the lock ring is adapted to be secured to the pin member such that the flange of the lock ring is swaged into the lock groove of the pin member and transformed to a bead that engages the lock groove
Implementation Method 2
the frangible portion of the pin member is broken off from the pin member at the breakneck groove, forming an exposed surface on the second smooth cylindrical portion
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A rivet (10) includes a pin member (12) having a head (34) and a lock groove (26), and a lock ring (14) having a flange (53). The flange (53) of the lock ring (14) is swaged into the lock groove (26) of the pin member (12) and transformed to a bead (54) that engages the lock groove (26), and a portion (P) of an outer surface (50) of the lock ring (14) deforms and is rotated inwardly. The rivet (10) is installed within a structure (56) such that the head (34) of the pin member (12) is flush with an outer surface (68) of a panel (64) and the portion (P) of the outer surface (50) of the lock ring (14) is flush with an outer surface (66) of another panel (62). The pin member (12) includes a frangible portion (28) that breaks off when the rivet (10) is installed.