Bicycle Wheel Spoke Threaded Segment Loosen-Proofing Design
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Solution Overview
Problem
Conventional bicycle wheel spokes experience nut loosening due to shock and vibration, leading to instability and safety issues, and existing loosen-proofing mechanisms often result in damage to the spoke, requiring frequent replacements.
Innovation Solution
A spoke design featuring multiple first thread sections and at least one second thread section with specific radii and pitch, allowing for a secure engagement between the nut and threaded segment without causing deformation or damage, ensuring the nut remains tightened.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-threaded buffering section with different pitch thread sections is used to prevent nut loosening, then the nut remains securely engaged, but the buffering section is prone to break or damage due to stress and torque
Solution Approach 1:
The patent changes the geometric parameters of the thread sections. The first thread section has a first pitch and the second thread section has a second pitch that is different from the first pitch. This parameter change creates differential threading that prevents nut loosening while distributing stress more evenly, avoiding concentration on a single non-threaded buffering section.
Solution Approach 2:
The threaded segment is segmented into multiple thread sections (first thread section and second thread section) with different pitches. This segmentation allows each section to handle different aspects of the loading, preventing any single section from bearing excessive stress that would lead to buffering section failure.
2Ease of manufacture
If a conventional single-pitch threaded segment is used, then the structure is simple and easy to manufacture, but the nut loosens due to shock and vibration during bicycle riding
Solution Approach 1:
The patent introduces a parameter change by using different pitches for the first and second thread sections. This maintains relative manufacturing simplicity while significantly improving nut engagement stability under dynamic loading conditions from shock and vibration during bicycle riding.
3Reliability
If the buffering section deforms to provide loosen-proofing effect, then the nut remains secure, but the deformation causes break or damage to the buffering section
Solution Approach 1:
By changing the pitch parameters between thread sections, the patent achieves loosen-proofing through controlled differential engagement rather than relying on deformation of a buffering section. This eliminates the buffer section breakage issue while maintaining the desired loosen-proofing effect, thereby extending spoke lifespan.
Solution Approach 2:
The patent converts the potentially harmful stress concentration that would damage a buffering section into a beneficial differential threading mechanism. The different pitches create a self-locking effect that provides loosen-proofing without requiring a deformable buffering section, thus preventing damage while achieving the same functional benefit.
Data Source
AI summary
A spoke of a bicycle rim has a spoke body having a connecting end and a threaded segment formed on the connecting end. The threaded segment has multiple first thread sections and at least one second thread section. The first thread sections have a major radius, a minor radius and a pitch. The at least one second thread section is formed between the first thread sections to form at least one loosen-proofing section between the first thread sections and has a major radius, a minor radius and a pitch. The major radius of the second thread section is smaller than the major radius of the first thread sections. The minor radius of the second thread section is larger than the minor radius of the first thread sections. The pitch of the second thread section is the same as that of the first thread sections.