Segmented Chain-Rings for Smooth Bicycle Shifting
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Solution Overview
Problem
Current bicycle transmission systems with derailleurs face limitations in smooth transition and continuous force transmission between chain-rings, leading to inefficiencies, wear, and reliability issues due to high friction, chain slippage, and complex shifting processes, especially with non-round chain-rings.
Innovation Solution
A chain-rings set with a segmented second chain-ring that allows axial displacement of its segments to engage the chain without reaching the same plane as the first chain-ring, ensuring optimal synchronization and power transmission through specific tooth profiles and angular displacements, enabling efficient shifting without derailleurs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If derailleurs are used for chain displacement between chain-rings, then shifting capability is achieved, but friction increases and reliability decreases
Solution Approach 1:
The patent removes the derailleur component from the system entirely. Instead of using a derailleur to push the chain laterally between chain-rings, the invention uses the chain's own tension and the geometric arrangement of segmented chain-rings to achieve automatic chain displacement. This extraction of the problematic component eliminates the friction and reliability issues associated with derailleur operation.
Solution Approach 2:
The chain transmission system performs shifting autonomously without external assistance. The segmented chain-rings are arranged in multiple planes, and when the chain engages one chain-ring, the geometry of the segments and chain tension automatically guides the chain to the next chain-ring in sequence. This self-service mechanism eliminates the need for separate shifting components and their associated friction and wear.
2Ease of operation
If derailleurs press on the chain to twist it laterally, then chain displacement is achieved, but friction increases and wear increases
Solution Approach 1:
The patent eliminates the derailleur pressing mechanism that causes lateral twisting and friction. Instead, the chain displacement is achieved through the geometric arrangement of segmented chain-rings in different planes, where the chain naturally transitions from one segment to another through its tension and the spatial configuration of the teeth.
Solution Approach 2:
The patent arranges chain-rings in multiple spatial planes rather than a single plane. This dimensional arrangement allows the chain to transition between chain-rings through vertical and lateral movement combined, eliminating the need for high-friction lateral twisting by a derailleur. The chain follows a natural path through the multi-planar geometry.
3Ease of operation
If chain displacement is achieved through lateral twisting, then shifting is possible, but the process becomes complex and less reliable
Solution Approach 1:
The patent divides each chain-ring into multiple segments arranged in different planes. This segmentation creates a staircase-like arrangement where the chain can transition from one segment to another in a systematic manner. The segmentation simplifies the shifting process by breaking down the complex lateral twisting into smaller, more manageable geometric transitions between segments.
4Adaptability or versatility
If multiple chain-rings and sprockets are used to increase gear ratios, then versatility is improved, but the complexity of the transmission system increases
Solution Approach 1:
The patent arranges chain-rings in multiple spatial planes rather than a single plane. This multi-planar arrangement allows for a greater number of chain-rings to be packed into a compact space, increasing the range of gear ratios without proportionally increasing the lateral spread and complexity of the transmission system. The vertical stacking of chain-rings optimizes space utilization.
Data Source
AI summary
Chain-rings set, for a power transmission system, which includes a chain, a first chain-ring, a second chain-ring where the first chain-ring is formed by a support part of the teeth and a teeth part, where the second chain-ring is formed by segments each formed by a support part of the teeth and a teeth part, which includes axial displacement means of the segments, where an up-shift segment of the segments has a first tooth which is the first which is engaged with the chain in the rotation movement, and where the displacement means are configured for moving the up-shift segment to an engaging position such that the first tooth can engage with an engaging link of the up-shift section of the chain, when the chain is engaged in the small chain-ring, and without the support part of the up-shift segment reaching the same plane than the support part of the first chain-ring, and to successively displace the other independent segments to an engaging position with the chain without the support parts of the independent segments reaching the same plane than the support part of the first chain-ring.