Bicycle Brake Assembly Synchronization Mechanism

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Solution Overview

Problem

Conventional bicycle brakes experience unsynchronized pivotal movements between the first and second brake arms due to uneven rotational resistance and biasing forces, leading to inefficient braking and increased operational effort, especially when exposed to contaminants like water and mud.

Innovation Solution

A bicycle brake device featuring a biasing member and a communicating member that allows the first and second brake arms to pivot in synchronization, with a biasing force adjustment mechanism to optimize braking and releasing operations, ensuring synchronized movement and reduced operational effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional bicycle brakes use separate brake arms with independent pivot mounting, then the brake structure is simple and easy to manufacture, but the brake arms experience unsynchronized pivotal movements due to uneven rotational resistance and biasing forces

Engineering Contradiction:
Improvebrake structure simplicityVSAvoidbrake arm synchronization
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent merges the first and second brake arms into a single integrated brake arm structure that pivots around a common pivot axis. This combination ensures that both brake shoes are actuated simultaneously through the shared pivot point, eliminating the synchronization problems that occur with separate brake arms having independent pivots.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated brake arm serves multiple functions: it acts as both the first and second brake arm, provides a common pivot mounting, and incorporates a communicating member that functions as both a structural link and a synchronization mechanism. This multi-functionality maintains structural simplicity while ensuring reliable synchronized operation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If bicycle brakes use complicated synchronizing structures to ensure synchronized brake arm movement, then brake arm synchronization is improved, but the device complexity and friction increase

Engineering Contradiction:
Improvebrake arm synchronizationVSAvoidsynchronizing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The brake arm and communicating member are integrated into a single unified structure. The communicating member is not a separate component but is formed as part of the brake arm itself, eliminating the need for additional synchronizing mechanisms while ensuring synchronized pivotal movement of both brake shoes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated brake arm structure performs multiple functions simultaneously: it provides the braking function, acts as the communicating member for synchronization, and serves as the structural link between the pivot axis and the brake shoes. This eliminates the need for separate synchronizing structures and reduces overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If bicycle brakes use strong return springs to overcome friction from synchronizing structures, then the brake releasing function is improved, but the operational effort required increases

Engineering Contradiction:
Improvebrake releasing functionVSAvoidoperational effort
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The patent extracts and eliminates the source of excessive friction by removing complicated separate synchronizing structures. By integrating the communicating member into the brake arm itself, the friction that would otherwise require strong return springs to overcome is significantly reduced, allowing for lighter springs and less operational effort.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The integrated brake arm structure with its built-in communicating member automatically ensures synchronized movement without requiring additional forces or complex mechanisms. The design itself provides the synchronization function, eliminating the need for extra friction-compensating features and reducing the force required for operation.

Inventive Principle:
Principle #25Self-service

4Ease of manufacture

If bicycle brakes expose pivot mounting portions to the environment, then the brake structure is simple and accessible, but contaminants like water and mud increase friction and affect performance

Engineering Contradiction:
Improvepivot mounting accessibilityVSAvoidcontaminant exposure
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The pivot mounting portion is nested within the integrated brake arm structure rather than being exposed on the exterior. The communicating member is positioned such that the pivot axis is protected within the brake arm assembly, shielding it from environmental contaminants while maintaining the structural simplicity and accessibility of the brake system.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution ensures synchronized pivotal movements of the brake arms during both braking and releasing operations, improving braking efficiency and reducing the operational effort required, while also providing better resistance to contaminants.

Implementation Method 1

a biasing member biasing the first brake arm and the second brake arm in a direction in which the first brake shoe mounting portion and the second brake shoe mounting portion are separated from each other

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a communicating member, also referred to as bias communication member, bias communicating link portion or simply as link portion, link member which allows the first brake arm and the second brake arm to pivot in synchronization

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 3

when a braking lever is gripped to perform a braking operation, braking is applied by reducing a distance between a first brake shoe and a second brake shoe that oppose each other and thereby sandwiching a rim portion of a wheel

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3000708B1Bicycle brake assembly
Publication Date: 2020.06.17 SHIMANO INC
  • EP3000708B1 patent drawingFigure 1
  • EP3000708B1 patent drawingFigure 2
  • EP3000708B1 patent drawingFigure 3

AI summary

The present invention is directed to various features of a bicycle brake device. A bicycle braking device comprises: a first brake arm having a first mounting portion pivotally mountable to a bicycle frame, a first brake shoe mounting portion to which a first brake shoe is mounted, and a first cable mounting portion to which a brake operating cable is mounted; a second brake arm having a second mounting portion pivotally mountable to the bicycle frame, and a second brake shoe mounting portion to which a second brake shoe is mounted; a biasing member biasing the first brake arm and the second brake arm in a direction in which the first brake shoe mounting portion and the second brake shoe mounting portion are separated from each other; and a communicating member, also referred to as bias communication member, bias communicating link portion or simply as link portion, link member which allows the first brake arm and the second brake arm to pivot in synchronization.