Dual-Thread Fastener Structure for Multi-Axial Bone Fixation
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Solution Overview
Problem
Current fastening devices do not adequately address the need for improved thread designs that provide enhanced resistance to multi-axial forces and load sharing, particularly in bone and tissue applications, while maintaining stability and reducing bone strain.
Innovation Solution
The development of fasteners with dual helical thread configurations, featuring angled and normal thread patterns that form interlocking valleys and undercut surfaces, which enhance bone fixation and load distribution by interlocking with bone tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional single thread patterns are used, then the fastener structure is simple, but the resistance to multi-axial forces is insufficient
Solution Approach 1:
The thread pattern is segmented into multiple distinct thread patterns (first thread pattern with angled top surface and normal bottom surface, second thread pattern with normal top surface and angled bottom surface) that operate in different planes and directions. Each thread pattern segment handles specific directional loads, collectively providing comprehensive resistance to multi-axial forces while maintaining individual thread simplicity.
Solution Approach 2:
The invention transitions from conventional single-plane thread patterns to multi-dimensional thread configuration by introducing thread patterns with surfaces angled at different orientations (including angles greater than 90 degrees relative to the shaft axis). This dimensional expansion allows the fastener to resist loads from multiple directions simultaneously, improving multi-axial force resistance without proportionally increasing complexity.
2Strength
If conventional thread designs are used, then manufacturing is simple, but load distribution and bone fixation are insufficient
Solution Approach 1:
Different regions of the thread pattern are assigned different geometric properties: the first thread pattern has an angled top surface for optimal load distribution in one direction, while the second thread pattern has a normal top surface for perpendicular load handling. This local differentiation of thread geometry optimizes bone fixation and load distribution in specific zones without requiring complete redesign of the entire thread structure.
Solution Approach 2:
The thread pattern employs asymmetric geometry where the top and bottom surfaces of each thread are angled differently relative to the shaft axis, with angles greater than 90 degrees. This asymmetry creates interlocking valleys that enhance mechanical interlocking with bone tissue, improving fixation strength and load distribution while remaining manufacturable through conventional threading processes.
3Stability of the object's composition
If traditional thread patterns are used, then the fastener provides basic fastening, but stability and bone strain reduction are inadequate
Solution Approach 1:
Multiple thread patterns with different geometric characteristics are merged into a single integrated fastener structure. The first thread pattern (with angled top surface) and second thread pattern (with normal top surface) work together synergistically, with their interlocking valleys providing enhanced mechanical interlocking. This combination improves fastener stability and reduces bone strain by distributing loads more effectively across the bone-fastener interface.
Data Source
AI summary
A fastener to resist loadings in multiple directions simultaneously is provided. The fastener utilizes multiple thread faces that extend outward from the center axis of the fastener in various directions.