Bicycle Front Derailleur Vertical Pivot Cable Routing
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Solution Overview
Problem
Conventional front derailleur devices face challenges in compact design, efficient cable routing, and secure attachment to modern bicycle frames with complex geometries, often requiring additional space and complex cable routing solutions.
Innovation Solution
The front derailleur device incorporates a cable guide and fixing device on the frame fixing part, allowing flexible cable routing and attachment options, including pivotable components and adjustable fastening systems, to optimize space usage and cable management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional side-swing derailleur mechanisms are used with two parallel pivoting lever arms, then the chain cage can be moved along a circular path in a predetermined orientation, but the mechanical components require significant space to the side of the frame tube
Solution Approach 1:
The patent inverts the traditional side-swing mechanism by making the chain cage pivot vertically instead of horizontally. The pivot axis is oriented vertically rather than laterally, allowing the chain cage to move in a vertical plane between chainrings. This inversion eliminates the need for extensive lateral space while maintaining the chain shifting function.
Solution Approach 2:
The patent changes the dimension of pivoting from horizontal (side-swing) to vertical (top-swing). By reorienting the pivot axis from a lateral to a vertical orientation, the mechanism utilizes the vertical dimension for chain cage movement, thereby reducing the horizontal space requirement and enabling compact integration with modern bicycle frame geometries.
2Productivity
If modern bicycle frame geometries with short chainstays and large wheel diameters are used, then the bicycle achieves improved performance characteristics, but there is relatively little space available behind the seat tube for derailleur components
Solution Approach 1:
The patent inverts the traditional derailleur orientation to pivot vertically rather than horizontally. This allows the derailleur components to be positioned in the limited vertical space behind the seat tube rather than requiring extensive lateral space, making it compatible with modern compact frame geometries that prioritize performance.
Solution Approach 2:
The patent adapts the derailleur mechanism to utilize the specific local space characteristics of modern bicycle frames. By implementing a vertical pivot arrangement, the design exploits the vertical clearance available behind the seat tube, matching the component layout to the local spatial constraints imposed by contemporary high-performance frame geometries.
3Ease of operation
If conventional cable routing along the seat tube is used, then the control cable can be routed to the derailleur, but complex frame geometries make this routing no longer advantageous
Solution Approach 1:
The patent changes the cable routing approach by guiding the control cable in a vertical direction from above rather than along the lateral path of conventional seat tube routing. This vertical cable guidance reduces complexity by providing a more direct and simpler routing path that accommodates complex frame geometries without requiring elaborate cable management solutions.
4Ease of operation
If a top-swing derailleur arrangement with a leaf spring bolted to the pivot arm is used, then the chain cage can pivot vertically, but the solution becomes bulky and has not become established in practice
Solution Approach 1:
The patent merges the spring mechanism and pivot assembly into a compact integrated unit. Rather than using a bulky leaf spring bolted to an external pivot arm, the design combines these elements into a streamlined configuration where the spring is incorporated within the pivot assembly structure, significantly reducing the overall volume of the derailleur assembly.
Solution Approach 2:
The patent creates a multi-functional pivot assembly that simultaneously provides vertical pivoting, spring loading, and cable attachment functions. This universal design eliminates the need for separate bulky components and achieves compact proportions by having each element serve multiple purposes within the integrated assembly.
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
This configuration enables a compact, functionally optimized design with variable cable routing and secure attachment to the bicycle frame, reducing installation space requirements and improving operational reliability.
Implementation Method 1
at least two joint struts which are rotatably displaceable relative to the frame fixing part and relative to the chain cage about bearing pins and pivot axes associated with these bearing pins
Data Source
Figure 1
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AI summary
The invention relates to a front derailleur assembly (10) for a bicycle derailleur system, comprising: - a frame fixing part (20) for mounting on a bicycle frame, - a pivotable joint assembly (22) relative to the frame fixing part (20), and - a chain cage (24) pivotable relative to the frame fixing part (20) via the pivotable joint assembly (22) for guiding and pivoting the bicycle chain, wherein the joint assembly (22) comprises at least two joint struts (66, 68) which are rotatably displaceable relative to the frame fixing part (20) and relative to the chain cage (24) about bearing pins (62, 64, 70, 72) and pivot axes associated with these bearing pins, wherein the pivot axes run substantially parallel to each other and, in the mounted state of the derailleur assembly (10) on a bicycle, are substantially vertically oriented or are inclined by a maximum of 30° to a vertically running axis.wherein the derailleur assembly (10) can be controlled via a control cable (64). In this derailleur assembly, it is provided that the control cable (64) can be guided relative to the bicycle frame via a cable guide (38) provided on the frame fixing part, that furthermore the control cable (64) can be secured to the derailleur assembly (10) via a cable fixing device (40), wherein the cable fixing device (40) is provided on the frame fixing part (20), and that the control cable (64) is guided between the cable fixing device (40) and the cable guide (38) via a cable deflection device (76), wherein the cable deflection device (76) is arranged on one of the pivot struts (66) of the pivot assembly (22) or on the chain cage (24).