Anti-Cross Thread Fastener with Shortened Transition Helix
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Solution Overview
Problem
Current anti-cross thread fasteners have a fixed and longer transitional thread contour length due to manufacturing limitations, leading to unnecessary extra length that does not contribute to the desired height transition, resulting in a longer helix that is not fully functional.
Innovation Solution
The transitional thread contour length is reduced by reconfiguring the first and second sections of the helix to form full-width standard thread contours, allowing for a shorter anti-cross thread fastener while maintaining the necessary height transition and functionality, achieved by controlling the peak height within acceptable limits and eliminating non-functional sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transitional thread contour length is increased to ensure smooth height transition between standard and anti-cross threads, then the transition functionality is improved, but the overall fastener length increases and non-functional sections are added
Solution Approach 1:
The patent applies local quality by varying the thread height at different positions along the helix. The transitional thread contour is designed to have its full height only at specific locations (where it blends with standard and anti-cross threads) while being reduced in height at intermediate positions. This localized height variation enables the transition function without requiring the entire transitional section to maintain full thread height, thereby reducing overall fastener length while preserving transition functionality.
2Strength
If the transitional thread contour maintains full height throughout its length to ensure structural integrity, then strength is improved, but the fastener becomes longer and heavier with non-functional sections
Solution Approach 1:
The patent implements local quality by providing full thread height only where structurally necessary (at the boundaries where the transitional thread blends with standard and anti-cross threads) while reducing thread height in the intermediate portions. This selective height distribution maintains structural integrity at critical locations while eliminating excess material in non-critical sections, thereby reducing fastener weight without compromising strength where needed.
Data Source
AI summary
A male anti-cross threading fastener comprising: a substantially round shank having a lead end, a torque end, and a plurality of male threads around a circumference of the shank, the plurality of male threads comprising: a standard thread around at least a portion of the circumference of the shank and having a standard thread contour, wherein a width and a thread angle of the standard thread enables engagement with corresponding female threads, wherein the major diameter of the standard thread is between a lower major diameter limit and a higher major diameter limit; a transitional thread around at least a portion of the circumference of the shank and having a transitional thread contour with a width and a thread angle similar to the width and thread angle of the standard thread that enables engagement with corresponding female threads; an anti-cross thread around at least a portion of the circumference of the shank and having an anti-cross thread contour and an outside diameter configured to promote alignment of the male anti-cross thread fastener with a female fastener; and a lead thread around at least a portion of the circumference of the shank and having a lead thread contour, and wherein the transitional thread contour has a height that transitions from the lower major diameter limit of the standard thread to the outside diameter of the anti-cross thread.