Bicycle Derailleur Chain Guide Adjustment Mechanism
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Solution Overview
Problem
Existing bicycle derailleurs lack effective mechanisms to restrict the movement of the chain guide at both retracted and extended positions, leading to inefficient gear shifting and potential chain derailment.
Innovation Solution
A bicycle derailleur design featuring a base member, a chain guide, and a linkage assembly with first and second adjusting members that pivotally couple the chain guide to the base member, allowing for precise adjustment of the chain guide's movement between retracted and extended positions, using threaded screws and tool access portions for optimal alignment and contact with the base member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If no adjustment mechanism is provided for the chain guide, then the structure is simpler, but the gear shifting precision deteriorates and chain derailment occurs
Solution Approach 1:
The patent applies parameter changes by providing adjustable limiting members that can be positioned at different locations along the linkage assembly. This allows the chain guide's movement range to be precisely controlled by changing the position parameter of the limiting members, thereby achieving accurate gear shifting without requiring a completely complex adjustment mechanism.
Solution Approach 2:
The patent segments the adjustment function by separating the limiting members from the main chain guide structure. The limiting members are independent components that can be individually adjusted and positioned, allowing precise control of the chain guide's movement extremes without complicating the overall structure. This segmentation enables simple yet effective adjustment capability.
2Reliability
If the chain guide movement range is not restricted, then the device is simpler to manufacture, but chain derailment occurs and reliability deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-positioning the limiting members on the linkage assembly before final assembly. The limiting members are installed at specific predetermined positions that correspond to the extreme movement positions of the chain guide, thereby preventing chain derailment before it can occur. This preliminary positioning ensures reliability without requiring complex post-assembly adjustments or complicated manufacturing processes.
3Measurement precision
If adjusting members are added to restrict chain guide movement, then gear shifting precision is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by designing the limiting members to serve multiple functions: they act as both position limiters and adjustment mechanisms. The same components that restrict the chain guide's movement also provide the adjustment capability for precise positioning. This multi-functionality reduces the need for separate adjustment devices, thereby improving precision without proportionally increasing device complexity.
Data Source
AI summary
A bicycle derailleur is basically provided with a base member, a chain guide, a linkage assembly and a first adjusting member. The chain guide is pivotally supported with respect to the base member between a retracted and an extended position. The linkage assembly includes a first link coupled to the base member about a first pivot axis and coupled to the chain guide about a second pivot axis. The linkage assembly includes a second link coupling the base member to the chain guide. The second link is farther from the bicycle frame than the first link when the base member is mounted to the bicycle frame. The first adjusting member is movably attached to the first link. The first adjusting member is configured to contact one of the base member and the chain guide to restrict movement of the chain guide at one of the retracted and extended positions.