Bicycle Derailleur Adjustable Rest for Stable Positioning
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Solution Overview
Problem
The existing coupling between the front derailleur body and the bicycle frame is prone to deformation during gear shifting, leading to imprecision and potential chain drop, especially in motorized systems where precise gear shifting is critical.
Innovation Solution
An adjustable rest mechanism is introduced, comprising a fixed and mobile part with a fastener, allowing the derailleur body to maintain a stable position through contact with the frame, using a separation spring and anti-loosening washer for quick and precise adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the derailleur body is coupled to the seat tube through a nut and support element, then the derailleur body is fixed to the frame, but the coupling deforms under reaction force during gearshifting causing position variation
Solution Approach 1:
The coupling system is divided into multiple functional elements: a support element with shaped seat, a coupling portion with locking nut, and a rest portion that contacts the frame tube. This segmentation allows each element to perform its specific function - the support element provides mounting, the nut provides locking, and the rest portion provides positional stability by preventing deformation.
Solution Approach 2:
The invention merges the coupling function and the positioning function into a single integrated system. The rest portion is integrated with the coupling mechanism, combining the functions of securing the derailleur body to the frame and preventing deformation under load into one unified structure.
2Reliability
If the coupling portion and support element are tightened to secure the derailleur body, then the derailleur body is firmly fixed, but deformation occurs under high chain tension during gearshifting
Solution Approach 1:
The rest portion is designed to preemptively counteract the deforming reaction force before it can cause significant displacement. By providing a contact surface against the frame tube, it creates an opposing force that balances the chain tension-induced reaction force, preventing the coupling portion and support element from deforming under load.
3Device complexity
If the derailleur body is mounted cantilevered on the support element, then the structure is simple, but the position varies under reaction force during gearshifting
Solution Approach 1:
The rest portion acts as an intermediary element between the derailleur body and the frame tube. It provides a contact interface that mediates the interaction between the moving derailleur body and the stationary frame, preventing direct transmission of deforming forces to the coupling mechanism while maintaining structural integrity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The adjustable rest ensures precise and stable gear shifting by maintaining the derailleur body's position, reducing deformation and improving shifting accuracy across various conditions and derailleur types.
Implementation Method 1
a separation spring acting for pushing the two parts from one another
Implementation Method 2
a means for fixing said mobile part with respect to said fixed part in a desired operative angular position, wherein said means for fixing comprises a separation spring acting for pushing the two parts from one another and an anti-loosening washer
Data Source
AI summary
A device for connecting a front derailleur to the front tube of a bicycle. The device is fixed to the derailleur and the front tube at a predetermined position and includes an adjustable rest for contacting the front tube and positioning the derailleur.