Bicycle Chain Outer Link Plate Geometry for Multi-Sprocket Strength
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Solution Overview
Problem
Bicycle chains face challenges in maintaining strength and chain-holding performance, especially when the number of sprocket wheels increases, due to reduced thickness of the outer link plates.
Innovation Solution
The bicycle chain design incorporates specific geometries and dimensions for the outer link plates, including defined radial distances, curvature radii, and chamfers, which enhance strength and chain-holding performance even with reduced thickness, by optimizing the link plate dimensions and edge configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the thickness of the outer link plate is reduced to accommodate a larger number of sprocket wheels, then the chain can fit more sprockets, but the strength of the outer link plate deteriorates
Solution Approach 1:
The patent applies local quality by creating a recessed portion in the intermediate portion of the outer link plate, concentrating material distribution in critical areas. This recessed design allows the link plate to maintain adequate thickness and strength at the intermediate portion while accommodating the overall reduced thickness needed for multiple sprocket wheels, thus resolving the contradiction between adaptability and strength.
2Adaptability or versatility
If the thickness of the outer link plate is reduced to accommodate a larger number of sprocket wheels, then the chain can fit more sprockets, but the chain-holding performance deteriorates
Solution Approach 1:
The recessed portion creates localized structural optimization that maintains chain-holding performance in critical areas while allowing overall thickness reduction. The strategic placement of the recessed portion preserves material in areas essential for chain engagement, thereby maintaining reliability despite reduced overall thickness for multi-sprocket compatibility.
Solution Approach 2:
The recessed portion introduces a curved geometric feature that optimizes stress distribution and material utilization. This curvature in the intermediate portion enhances the structural efficiency of the link plate, maintaining chain-holding performance while enabling reduced thickness for better sprocket compatibility.
3Reliability
If the minimum distance between intermediate edges is increased to improve chain-holding performance, then chain-holding performance improves, but the link plate requires more material and cannot be thinned
Solution Approach 1:
The recessed portion creates a localized structural feature that optimizes the minimum distance between intermediate edges only where necessary for chain-holding performance. This local optimization allows the link plate to maintain adequate performance metrics while keeping the overall thickness reduced for multi-sprocket wheel compatibility.
Data Source
AI summary
A bicycle chain comprises a first outer link plate. The first outer link plate comprises a first outer-link end portion, a second outer-link end portion, a first outer-link intermediate portion, and a first outer-link longitudinal centerline. The first outer-link end portion, the second outer-link end portion and the first outer-link intermediate portion define a first outer-link outer peripheral edge. The first outer-link outer peripheral edge comprises a first outer-link end edge, a second outer-link end edge, and a pair of first outer-link intermediate edges. A first radial distance is defined from a first outer-link center axis to the first outer-link end edge in a perpendicular direction. A minimum distance is defined between the pair of first outer-link intermediate edges in the perpendicular direction. The minimum distance is smaller than 200% of the first radial distance and is equal to or larger than 5 mm.