Bicycle Derailleur Stopper Mechanism for Rocking Stability

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Solution Overview

Problem

Current bicycle rear derailleur designs require a widened base member and elongated mounting axle to prevent rocking movement, which is undesirable due to increased mass and space considerations.

Innovation Solution

A stopper mechanism is integrated into the base member of the rear derailleur, allowing for adjustable angular stop positions without lengthening the mounting axle or widening the base member, using a slot and support portion configuration with a stopper and washer to maintain stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the base member is spaced apart from the bicycle frame using a stopper member, then the base member is stable, but the base member must be widened and the mounting axle must be elongated to avoid rocking movement

Engineering Contradiction:
Improvestability of base memberVSAvoidsize of base member and mounting axle
Core Design Contradiction:
Stability of the object's compositionVSVolume of moving object

Solution Approach 1:

The stopper member is positioned within the plane of the base member rather than extending perpendicular to it. This dimensional repositioning allows the stopper to effectively prevent rocking movement without requiring the base member to be widened or the mounting axle to be elongated, thus resolving the contradiction between stability and compact size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If the base member is widened and mounting axle is elongated to prevent rocking movement, then rocking stability is improved, but mass and space efficiency deteriorate

Engineering Contradiction:
Improverocking stabilityVSAvoidmass of base member and mounting axle
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

By repositioning the stopper member within the base member's plane, the design achieves rocking stability without increasing the dimensions or mass of the base member and mounting axle. This dimensional strategy eliminates the need for additional material while maintaining structural stability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Stability of the object's composition

If the base member is widened and mounting axle is elongated to prevent rocking movement, then rocking stability is improved, but space efficiency deteriorates

Engineering Contradiction:
Improverocking stabilityVSAvoidspace occupied by base member and mounting axle
Core Design Contradiction:
Stability of the object's compositionVSVolume of moving object

Solution Approach 1:

The stopper member is strategically positioned within the plane of the base member, allowing it to effectively prevent rocking movement without requiring the base member to be widened or the mounting axle to be elongated. This maintains compact dimensions and optimizes space efficiency while achieving the desired stability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP1897797B1Bicycle derailleur
Publication Date: 2010.03.31 SHIMANO INC
  • EP1897797B1 patent drawingFigure 1~2
  • EP1897797B1 patent drawingFigure 3
  • EP1897797B1 patent drawingFigure 4~5

AI summary

A bicycle derailleur mounting structure includes a base member (26) and a stopper (36). The base member (26) includes a first portion (32) configured for attachment to a bicycle frame (14). The first portion (32) of the base member has a first side surface (40) and a second side surface (42) with an aperture (44) extending between the first and second side surfaces. The stopper (36) is coupled to the base member (26) between the first and second side surfaces. The stopper is configured for setting an angular position of the base member relative to the bicycle frame.