Anti-False Thread Fastener Lead Profile for Cross-Thread Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing threaded fasteners often experience false threading due to manufacturing variations, misalignment, and inconsistent lead thread profiles, leading to structural damage and assembly failures.
Innovation Solution
A male anti-false thread fastener member with a lead thread that maintains a consistent, curved profile and constant height change, designed to prevent engagement with grooves in internal threads, ensuring proper alignment and reducing the risk of false threading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional lead threads with variable profiles are used, then manufacturing is easier and adaptability is higher, but false threading occurs due to engagement with grooves in internal threads
Solution Approach 1:
The patent applies parameter changes by modifying the lead thread profile from a traditional variable cross-sectional shape to a consistent rectangular cross-section throughout its length. This parameter change ensures that the lead thread maintains uniform dimensions and shape, preventing engagement with grooves in internal threads and eliminating false threading while simplifying the manufacturing process
Solution Approach 2:
The patent implements homogeneity by making the lead thread cross-section uniform along its entire length, rather than varying as in traditional designs. This homogeneous rectangular profile ensures consistent engagement characteristics and prevents false threading by eliminating the variable geometry that causes engagement with internal thread grooves
2Ease of operation
If lead threads with pointed peaks are used, then initial engagement is easier, but false threading occurs when peaks engage grooves in internal threads
Solution Approach 1:
The patent applies curvature by replacing the pointed peak of traditional lead threads with a rounded or flattened top surface. This curved modification allows the lead thread to smoothly engage with the internal thread while preventing concentrated stress at a point, thereby avoiding false threading caused by peak engagement with internal thread grooves
3Adaptability or versatility
If lead threads with varying heights are used, then adaptation to different assembly conditions is improved, but consistent alignment with internal threads becomes difficult
Solution Approach 1:
The patent applies parameter changes by fixing the lead thread height and cross-sectional dimensions to constant values throughout its length, rather than allowing variation. This parameter standardization ensures consistent alignment with internal threads while maintaining adaptability through the overall lead thread geometry and length
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~4E
AI summary
A male anti-false thread fastener member (10) having features, including: a shank that has a lead end and a tool engagement end; a head formed at the tool engagement end of the shank; at least one male fastening thread (15) formed on the exterior of the shank as a plurality of thread windings adapted to mate with a corresponding female fastening thread formed in an interior of a female fastener member; at least one male lead thread (17) formed on the exterior of the shank at the lead end that is at least a half winding around the shank and comprises curved profile defined by an arc having a radius (R) approximately equal to a radius of an arc that is tangent to both flanks of a thread profile of the at least one male fastening thread (15) and below the pitch line of the at least one male fastener thread (15).