Bicycle Brake Disc Axial Locking for Connection Reliability

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Solution Overview

Problem

Bicycle brake discs made in two components face reliability issues due to potential damage or breaking at connection points, which can compromise braking quality and safety, especially in racing bicycles.

Innovation Solution

A brake disc design featuring a first component with a braking track made of a strong material and a second component with a radially inner annular portion for hub coupling, along with axial locking members and shape couplings that maintain mutual pressure and rotational constraint between components, even in case of damage or breaking, ensuring continued braking functionality albeit with reduced efficiency until replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If the brake disc is made in two components (steel braking track and aluminum spider) to reduce weight, then the weight of the brake disc is reduced, but the reliability deteriorates due to potential damage or breaking at connection points

Engineering Contradiction:

Improveweight of brake discVSAvoidreliability of connection between components

Core Design Contradiction:

Weight of moving objectVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by providing axial locking members that maintain mutual pressure between the steel braking track and aluminum spider components. This pre-established pressure connection compensates for potential connection failures, ensuring that even if some connection portions are damaged, the components remain securely connected through the sustained pressure from the locking members, thus preventing complete separation and maintaining braking functionality.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Duration of action of stationary object

If the connection between first and second component allows relative radial and axial clearance to stop thermal dilations, then the durability is improved by reducing thermal stresses, but the reliability deteriorates due to potential connection damage

Engineering Contradiction:

Improvedurability of brake discVSAvoidreliability of braking function

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The axial locking members provide beforehand cushioning by maintaining continuous mutual pressure between the braking track and spider components. This pre-established pressure connection ensures that even when relative clearance allows thermal expansion, the components remain securely connected and cannot separate completely, thus maintaining braking functionality despite the clearance designed for thermal management.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the connection between first and second component is made extremely reliable to guarantee braking quality, then the reliability is improved, but the device complexity increases

Engineering Contradiction:

Improvebraking qualityVSAvoidcomplexity of connection structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies merging by integrating the axial locking members as part of the hub assembly rather than as separate external fastening components. The locking members are incorporated into the existing hub structure, combining the functions of hub mounting and component retention into a unified assembly, thus achieving reliable component connection without significantly increasing overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

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

Enhances the strength and reliability of the braking track, maintaining sufficient braking capability even with damaged connections, and allows for easier replacement, thus ensuring safety and performance.

Implementation Method 1

axial locking members active on the radially inner annular portions of the first and of the second component to keep said radially inner annular portions of the first and of the second component under mutual pressure

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

the friction generated by the contact between pads and braking track

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 3

a grooved radially inner surface (i.e. a radially inner surface that extends longitudinally and is provided with longitudinal grooves), which is mounted on a matching grooved radially outer surface

Methodology Applied

Scientific EffectGeometric interlocking: Geometry

Data Source

PatentUS10330161B2Brake disc for a bicycle

Publication Date: 2019.06.25 CAMPAGNOLO SRL

AI summary

A brake disc for a bicycle comprising a first component made of a first material and having a braking track configured to cooperate with brake pads. A second component is made of a second material and having (i) a radially inner annular portion for coupling with a hub of a bicycle wheel and (ii) a plurality of radially outer portions for connecting to said first component at a respective plurality of connection portions of said first component. The first component further comprises a radially inner annular portion connected to said braking track, and the brake disc comprises axial locking members active on the radially inner annular portions of the first and of the second component to keep said radially inner annular portions of the first (30) and of the second component under mutual pressure.