Front Derailleur Adjustable Linkage Rest Position

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Solution Overview

Problem

Existing front derailleurs lack an efficient mechanism for adjusting the fixed rest position of the movable member relative to the fixed member, which affects the chain shifting performance and precision.

Innovation Solution

The front derailleur incorporates a fixing structure with a first bolt, a second bolt, and a movable abutment member, along with a positioning member, to adjustably couple the first link to the driven link, allowing for the establishment of a fixed rest position of the movable member with respect to the fixed member, enabling precise lateral movement and chain shifting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional fixed linkage assembly is used to connect the fixed member and chain guide, then the structure is simple, but the rest position of the movable member cannot be adjusted

Engineering Contradiction:

Improveadjustability of rest positionVSAvoidcomplexity of linkage assembly

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transforming the static, fixed linkage assembly into a dynamic, adjustable system. The adjustable linkage assembly allows the rest position of the movable member to be changed, enabling the derailleur to adapt to different chainring configurations and bicycle frame geometries. This resolves the contradiction by introducing adjustability without significantly complicating the overall structure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs parameter changes by allowing the linkage assembly to be adjusted to different positions and configurations. The adjustable linkage can be set to various rest positions, changing the geometric parameters of the chain guide's position relative to the fixed member. This enables the same basic structure to accommodate different chainring sizes and spacing, resolving the contradiction between adaptability and complexity.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the rest position is not adjustable, then the device is simple to manufacture, but the chain shifting precision is poor

Engineering Contradiction:

Improveprecision of chain shiftingVSAvoidease of assembly

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies segmentation by dividing the linkage assembly into adjustable segments that can be independently positioned and secured. The linkage assembly includes multiple connection points and adjustment mechanisms that allow precise positioning of the chain guide relative to the fixed member. This segmented approach enables manufacturing precision while maintaining ease of assembly through modular components.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs preliminary action by providing pre-configured adjustment mechanisms and pre-positioned mounting points in the linkage assembly. The adjustable linkage comes with built-in features that facilitate precise positioning before final assembly, allowing the rest position to be set accurately during installation. This resolves the contradiction by embedding precision-adjustment capabilities into the design without significantly complicating the manufacturing process.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the linkage assembly is rigidly fixed, then the structure is stable, but the rest position cannot be adjusted for different chainring configurations

Engineering Contradiction:

Improvecompatibility with different chainring configurationsVSAvoidstability of linkage structure

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by creating a linkage assembly that is stable in its fixed position but adjustable when needed. The adjustable linkage maintains structural stability during operation while allowing the rest position to be changed between different chainring configurations. This resolves the contradiction by providing both stability during use and adaptability for different applications.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent employs universality by designing the adjustable linkage assembly to work with multiple chainring configurations and bicycle frame types. The linkage can be adjusted to accommodate different chainring sizes, spacing, and positions, making a single derailleur design compatible with various bicycle setups. This multi-functionality resolves the contradiction between stability and adaptability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9776685B2Front derailleur

Publication Date: 2017.10.03 SHIMANO INC

AI summary

A front derailleur basically includes a fixed member, a movable member, a driven link and a first link. The fixing member is configured to be fixed to a bicycle frame. The movable member is movably supported with respect to the fixed member. The driven link is operatively coupled to the movable member. The first link movably connects the movable member to the fixed member, and is adjustably coupled to the driven link in a fixed position by a fixing structure to establish a fixed rest position of the movable member with respect to the fixed member.