Bicycle Brake Lever Geometry for Precise Hydraulic Seal Positioning
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Solution Overview
Problem
Existing bicycle control devices face challenges in efficiently adjusting the position of the primary seal relative to the master cylinder, leading to suboptimal hydraulic pressure application and ergonomic issues, while also being costly and complex in design.
Innovation Solution
The control device incorporates adjustable mechanisms, such as a multi-position cam, to precisely locate the piston assembly and primary seal, integrates components for reduced complexity and cost, and features a high-pivot brake lever and angled master cylinder for ergonomic design and smooth actuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If existing adjustment mechanisms are used to position the primary seal relative to the master cylinder, then the device can be adjusted, but the design becomes costly and complex
Solution Approach 1:
The patent combines the adjustment mechanism with the existing cam structure in the brake lever assembly. The cam profile itself serves as the adjustment mechanism, eliminating the need for separate adjustment components. This merging reduces part count and complexity while maintaining positioning precision through the cam's geometric design.
Solution Approach 2:
The patent introduces an adjustable cam profile that can be repositioned along the lever arc to dynamically adjust the primary seal position. This dynamic adjustment capability allows the system to adapt to different wear conditions and performance requirements without requiring complex mechanical adjustment devices.
2Ease of operation
If traditional brake lever designs are used, then the structure is simple, but ergonomic performance and braking efficiency are suboptimal
Solution Approach 1:
The patent positions the pivot point in a higher location, creating a three-dimensional lever arc that better aligns with natural finger motion. This spatial repositioning improves ergonomics by matching the lever pull direction with the rider's finger movement, reducing wrist strain and improving control.
Solution Approach 2:
The patent modifies the lever arm geometry and pivot position parameters to optimize the mechanical advantage and lever arc. By changing these geometric parameters, the design achieves better ergonomic performance and braking efficiency while maintaining structural simplicity through the fundamental lever mechanism.
3Productivity
If the master cylinder is positioned conventionally, then the design is straightforward, but hydraulic pressure application is inefficient
Solution Approach 1:
The patent positions the master cylinder and primary seal to optimize hydraulic pressure generation before the lever is actuated. The pre-positioning of the seal relative to the master cylinder bore ensures immediate and efficient pressure application when the lever is pulled, eliminating dead space and improving response time.
Solution Approach 2:
The patent optimizes the master cylinder internal geometry and seal positioning to improve hydraulic fluid displacement efficiency. By carefully designing the seal travel distance and master cylinder bore dimensions, the system achieves more efficient conversion of mechanical lever movement into hydraulic pressure, improving braking responsiveness.
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 allows for efficient hydraulic pressure application with minimal lever movement, reduces component costs and weight, and enhances ergonomic performance by aligning with natural finger motion, thus improving braking and shifting efficiency.
Implementation Method 1
a hydraulic brake system that applies pressure to a rotating part, a rotating wheel, or a disc mounted to the rotating wheel
Data Source
AI summary
A control device includes a housing having a base portion and an extension portion. The base portion of the housing has an inward facing side and an outward facing side. The control device includes a lever coupled to and pivotable relative to the housing, and a master cylinder portion supported by the housing. The master cylinder portion has a hollow fluid cylinder. The control device also includes a piston assembly supported by the housing. The piston assembly is movable relative to the master cylinder portion. At least part of the piston assembly is disposed within the master cylinder portion. The master cylinder portion is angled relative to the outward facing side of the base portion of the housing, such that the first end of the fluid cylinder is closer to the outward facing side than the second end of the fluid cylinder is relative to the outward facing side.