Asymmetric Hex Fastener Head for Weight Reduction
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Solution Overview
Problem
Traditional hex-head fasteners are over-designed for weight, leading to inefficiencies in torque transfer and material usage, which hinders efforts to reduce vehicle mass and improve gas mileage as per EPA regulations.
Innovation Solution
A fastener design with a hex-shaped lower perimeter and a differently shaped upper perimeter, utilizing four contact points for torque transfer instead of six, reducing material usage while maintaining structural integrity through a chamfered wall configuration, allowing for efficient torque application and weight reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If traditional hex-head fastener design is used, then torque transfer is achieved through six contact points, but weight and material usage are excessive
Solution Approach 1:
The fastener head employs an asymmetric geometry where the lower perimeter features a hex shape for torque application while the upper perimeter has a different shape. This asymmetric design reduces material usage and weight while maintaining effective torque transfer through four optimized contact points instead of the traditional six, directly resolving the contradiction between weight reduction and functional complexity
Solution Approach 2:
The invention extracts and removes unnecessary material from the traditional hex-head design by implementing a non-uniform head geometry. The upper portion of the head has a reduced perimeter compared to the lower hex portion, eliminating excess material that does not contribute to torque transfer functionality, thereby reducing fastener weight while preserving essential mechanical properties
2Loss of substance
If traditional hex-head design with six contact points is used, then torque application is standardized, but material usage is inefficient
Solution Approach 1:
The invention changes the geometric parameters of the fastener head by transitioning from a uniform hexagonal shape to a variable perimeter design. The lower perimeter maintains hex geometry for standardized torque application while the upper perimeter is modified with reduced dimensions, optimizing material distribution to four key contact zones and eliminating redundant material while preserving torque transfer reliability
3Weight of moving object
If hex-shaped head with uniform perimeter is used, then manufacturing is standardized, but weight reduction potential is lost
Solution Approach 1:
The fastener head is segmented into distinct geometric zones: a lower hexagonal perimeter portion for torque application and an upper perimeter portion with different geometry. This segmentation allows each zone to be optimized independently - the lower portion maintains compatibility with standard hex tools while the upper portion is tailored for weight reduction, and the transition between zones can be achieved through conventional manufacturing processes
Data Source
AI summary
An improved fastening device includes a shank portion with a first end and a second end disposed from the first end. The fastening device includes a head portion disposed adjacent the second end of the shank portion The head portion of the fastening device includes a lower perimeter adjacent the second end of the shank portion, an upper perimeter disposed away from the lower perimeter and a body portion extending between the lower perimeter and the upper perimeter. The head portion is configured to engage a standard hex-shaped socket. The lower perimeter of the head portion has a generally hex shape and the upper perimeter has a different shape than the lower perimeter.