Disc Brake Guide Sleeve Interlock to Prevent Guide Bolt Loosening

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Solution Overview

Problem

Conventional disc brake guide bolts tend to loosen due to rotational movement of the guide sleeve, which is transmitted as friction to the bolt, especially under repeated forward and reverse vehicle movements, with previous solutions only addressing the symptom rather than the cause.

Innovation Solution

A rotational fixing mechanism that interlocks the guide sleeve and brake carrier to inhibit both rotational and translational movements, using a connector system with cavities and deformable receiving portions to create a press-fit connection, thereby preventing undesirable movement and loosening of the guide bolt.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a guide bolt is used to retain the guide sleeve, then the guide pin can be assembled and the caliper can slide, but the guide bolt may rotate and loosen under repeated forward and reverse vehicle movements

Engineering Contradiction:
Improvesliding functionVSAvoidbolt retention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A rotational fixing mechanism is introduced as an intermediary component between the guide sleeve and brake carrier. This fixing includes a recess in the brake carrier and a protrusion on the guide sleeve that engage with each other, preventing rotational movement of the guide sleeve relative to the brake carrier, thereby protecting the guide bolt from loosening

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The rotational fixing is installed before the guide bolt is subjected to loosening forces. The protrusion and recess are designed to engage first, establishing a rotational constraint that prevents the guide bolt from rotating and loosening during subsequent operation

Inventive Principle:
Principle #10Preliminary action

2Reliability

If lock patches are used to inhibit rotation of the guide bolt, then bolt loosening is prevented, but the solution only addresses the symptom rather than the cause

Engineering Contradiction:
Improvebolt retentionVSAvoidfixing mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The rotational fixing mechanism extracts and addresses the root cause of the problem by preventing guide sleeve rotation, rather than merely applying lock patches to the guide bolt. This removes the source of the loosening issue while maintaining simplicity

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If the guide sleeve is allowed to rotate freely, then assembly is simple, but rotational movement transmits friction to the guide bolt causing loosening

Engineering Contradiction:
Improveassembly simplicityVSAvoidfriction-induced rotation
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The protrusion and recess are designed to engage in a press-fit manner, converting the potential harmful rotational friction into a beneficial mechanical interlock. The engagement surfaces are configured to resist rotational forces while maintaining assembly simplicity

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively restricts rotational and translational movements of the guide sleeve relative to the brake carrier, preventing bolt loosening and enhancing assembly alignment, thus ensuring stable brake performance and reducing operator error.

Implementation Method 1

The receiving portion is deformable during the assembly of the rotational fixing

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

an inter-connection to engage the sleeve portion and receiving portion when the sleeve portion is received by the receiving portion

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Implementation Method 3

the inter-connection is also configured to engage the sleeve portion and receiving portion so as to restrict translation of the guide sleeve relative to the brake carrier

Methodology Applied
Scientific EffectMechanical Constraint: Mechanical Fastener

Data Source

PatentEP3133312B2Rotational fixing for a guide pin of a disc brake and method thereof
Publication Date: 2024.05.22 MERITOR HEAVY VEHICLE BRAKING SYSTEMS (UK) LIMITED
  • EP3133312B2 patent drawingFigure 1
  • EP3133312B2 patent drawingFigure 2
  • EP3133312B2 patent drawingFigure 3a

AI summary

The present invention relates to rotational fixing and method for fixing a guide pin of a disc brake. The fixing comprises a sleeve portion of a guide sleeve, a receiving portion of a brake carrier to receive the sleeve portion, and an inter-connection to engage the sleeve portion and receiving portion so as to at least restrict rotation of the guide sleeve relative to the brake carrier when the sleeve portion is received by the receiving portion. The inter-connection may be further configured to engage the sleeve portion and receiving portion so as to at least restrict translation of the guide sleeve relative to the brake carrier when the sleeve portion is received by the receiving portion. The inter-connection may comprise a first cavity formed in the sleeve portion, a second cavity formed in the receiving portion and a connector co-locatable in the first cavity and the second cavity when the sleeve portion is received by the receiving portion. The receiving portion may be deformable and the second cavity may be formable when the sleeve portion is received by the receiving portion and a part of the connector is pushed into the receiving portion. The receiving portion may comprise a recess formed in the brake carrier in which the sleeve portion can be fitted so as to further restrict translation of the sleeve portion relative to the brake carrier, and comprise a receiving face disposed in the recess.