Swaged Stud Lockbolt With Breakoff Pull Portion for Reliable Preload
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Solution Overview
Problem
Existing two-piece swaged fasteners, or lockbolts, face challenges in securely fastening workpieces due to limitations in design and material compatibility, particularly in aerospace and space vehicle applications.
Innovation Solution
A fastener system comprising a pin member with a swage collar that includes a threaded portion, lock grooves, and a pull portion, where the collar is swaged into the lock grooves to secure workpieces, with features like breakneck grooves and gripping means for easy installation and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a two-piece swaged fastener system is used to secure workpieces, then the fastening strength and reliability are improved, but the installation complexity and time consumption increase due to multiple components and precise alignment requirements
Solution Approach 1:
The patent combines the pin member and collar into a two-piece system where the collar is swaged onto the pin, merging the fastening and locking functions into an integrated assembly that maintains high reliability while reducing the number of separate components compared to traditional multi-part fastening systems
Solution Approach 2:
The fastener is divided into two functional segments: a pin member with lock grooves and a collar that swages onto it. This segmentation allows each component to be optimized independently for its specific function while maintaining overall system reliability and simplifying manufacturing and installation
2Strength
If a swage collar is used to secure the pin member, then the fastening strength is improved, but the installation precision requirements increase due to the need for proper swaging alignment
Solution Approach 1:
The pin member is pre-formed with lock grooves during manufacturing, and the collar is designed with predetermined swaging features. This preliminary preparation eliminates the need for precise alignment during installation, as the components are designed to self-align and swage together easily while maintaining high fastening strength
Solution Approach 2:
The collar undergoes a swaging process that changes its physical parameters (shape, density, hardness) from a loose fit to a tightly bonded state. This parameter change allows the collar to conform to the pin member without requiring high alignment precision, while still achieving strong fastening
3Reliability
If lock grooves are provided on the pin member, then the locking reliability is improved, but the manufacturing complexity increases due to additional forming operations
Solution Approach 1:
The lock grooves are pre-formed on the pin member during the initial manufacturing process using standard forming operations. This preliminary action ensures consistent groove geometry and depth, providing reliable locking engagement while avoiding the need for complex post-processing or assembly operations
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 system provides secure fastening of workpieces with visual installation confirmation and ease of removal, suitable for aerospace and space vehicle applications.
Implementation Method 1
a swage collar adapted to be swaged into the at least one lock groove of the lock portion of the pin member
Data Source
Figure 1~1A
Figure 1B~1C
Figure 2~2A
AI summary
A fastener including a pin member having a shank portion, a threaded portion having a thread, a lock portion having at least one lock groove, and a pull portion located having at least one pull groove. The threaded portion is adapted to be engaged threadedly with a threaded hole of a workpiece to install the pin member therein. The fastener includes a swage collar adapted to be installed into the at least one lock groove of the lock portion to secure a plurality of workpieces. The pull portion is adapted to break off when the fastener is installed.