Handlebar Brake Lever Pivot Layout for Finger-Friendly Operation

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Solution Overview

Problem

Existing human-powered vehicle operating devices do not effectively optimize the movement of the operating member for user finger movements, leading to suboptimal operability.

Innovation Solution

The operating device incorporates a base with a hole containing a piston, an operating member pivotally coupled to the base about a first pivot axis closer to the mounting axis, and an intermediate member to transmit pivotal movements, allowing for improved finger-friendly operation and reduced device size through strategic placement of pivot axes and a hydraulic chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the first pivot axis is positioned closer to the mounting axis than the second pivot axis, then the operability is improved by matching finger movement, but the device structure becomes more complex

Engineering Contradiction:
ImproveoperabilityVSAvoiddevice structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The intermediate member acts as a mediator between the operating member and the piston, enabling the complex pivot axis arrangement to achieve finger-friendly motion transformation while maintaining a relatively simple overall structure. The intermediate member with its cam surface and follower mechanism translates the pivotal motion into suitable linear motion for the piston.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the operating device is made smaller by adjusting pivot axis positions, then the compactness is improved, but the finger movement suitability may be compromised

Engineering Contradiction:
Improvedevice sizeVSAvoidfinger movement suitability
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

The invention optimizes the geometric parameters of the pivot axes positions and the cam surface profile to achieve a compact device size while maintaining suitable finger movement characteristics. By carefully selecting the distances and angles of the pivot axes relative to each other, the device achieves small dimensions without sacrificing operability.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the piston stroke to pivot angle ratio is adjusted via cam surface, then the actuation efficiency is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveactuation efficiencyVSAvoidcam surface precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The cam surface is designed to provide the necessary motion transformation only over the required operating range, rather than over the entire possible range of motion. This allows for adequate actuation efficiency while reducing the overall precision requirements, as the cam surface needs to be precise only within the functional operating envelope.

Inventive Principle:
Principle #16Partial or excessive action

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 enhances operability by aligning the pivot axis with user finger movements, improves device compactness, and optimizes the use of space for a reservoir chamber, making the device more suitable for various user hand shapes and sizes.

Implementation Method 1

The base and the piston define a hydraulic chamber in the hole

Methodology Applied
Scientific EffectHydraulic pressure transmission: Pascal's Law

Data Source

PatentUS20230257060A1Operating device for human-powered vehicle
Publication Date: 2023.08.17 SHIMANO INC
  • US20230257060A1 patent drawing
  • US20230257060A1 patent drawing
  • US20230257060A1 patent drawing

AI summary

An operating device for a human-powered vehicle comprises a base, a piston, an operating member, an intermediate member, and a mounting structure. The base includes a hole. The piston is movably provided in the hole. The operating member is pivotally coupled to the base about a first pivot axis. The intermediate member is pivotally coupled to the base about a second pivot axis to transmit a pivotal movement of the operating member to the piston. The mounting structure is configured to couple the base and a handlebar of the human-powered vehicle. The mounting structure defines a mounting axis extending along the handlebar in a mounting state where the mounting structure couples the base and the handlebar. The first pivot axis is closer to the mounting axis than the second pivot axis in a perpendicular direction perpendicular to the mounting axis as viewed along the first pivot axis.