Tilting Roller Folding of Long Tyre Carcass Ends Around Bead Cores

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Solution Overview

Problem

Existing tire manufacturing methods struggle with folding long free ends of carcass plies around reinforcing bead wires, leading to creasing and incomplete folding due to circumferential thrust from conventional rolling actions.

Innovation Solution

A rolling-up installation with a folding device that applies a pressing member against the end section of the carcass ply in angular sectors, performing a tilting movement in pitch to fold the end section progressively and without circumferential thrust, using multiple pressing members if necessary to ensure complete folding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional rolling action is used to fold the carcass ply end around the reinforcing bead wire, then the folding operation can be performed, but the circumferential thrust causes creasing and incomplete folding of the ply end

Engineering Contradiction:
Improvefolding completenessVSAvoidcreasing and distortion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The folding operation is divided into multiple sequential stages, with each pressing member folding a specific angular sector of the carcass ply end. This segmentation allows controlled folding without circumferential thrust, preventing creasing while ensuring complete folding of the entire ply end around the bead wire.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a single roller that rolls circumferentially around the bead wire (conventional approach), the invention uses multiple pressing members that apply radial pressure inward toward the bead wire axis. This inverted approach eliminates circumferential thrust while maintaining folding effectiveness.

Inventive Principle:
Principle #13The other way round (Inversion)

2Strength

If the free ends of the carcass ply have large axial length to ensure robustness, then the tire structure is strengthened, but the folding operation becomes more difficult and cannot be completed by conventional rollers

Engineering Contradiction:
Improvecarcass ply robustnessVSAvoidfolding operation feasibility
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The long axial length of the free end is addressed by dividing the folding operation into multiple angular sectors, each handled by a dedicated pressing member. This allows the entire length to be folded systematically without requiring excessive axial travel by a single roller.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The folding operation transitions from a single circumferential dimension (conventional roller) to multiple angular dimensions around the bead wire. Pressing members are distributed around the circumference, enabling folding of long axial lengths by acting from multiple angular positions simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If a single pressing member is used to fold the carcass ply end, then the device structure is simple, but the folding operation is slow and cannot cover the entire circumference efficiently

Engineering Contradiction:
Improvenumber of pressing membersVSAvoidfolding operation speed
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

Multiple pressing members are combined to operate simultaneously on different angular sectors of the carcass ply end. This parallel operation significantly increases folding productivity compared to a single pressing member, while the modular design keeps individual component complexity manageable.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pressing members are designed with universal functionality to handle different angular sectors and can be replicated around the circumference. This multi-functional approach allows the same basic pressing mechanism to serve multiple positions, balancing device complexity with increased productivity.

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

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 method allows reliable, rapid, and reproducible folding of long carcass ply ends around reinforcing bead wires, preventing creasing and ensuring complete anchoring without tearing or stretching, suitable for tires with large axial lengths.

Implementation Method 1

a folding device which comprises at least one pressing member, such as a pressing roller, and which is arranged to apply said pressing member against the radially external face of the end section

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

to cause said pressing member to perform a tilting movement in pitch around the generating line of the reinforcement rod, so that the pressing member folds towards the radially internal face of the cylindrical wall of the carcass block

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP4363207B1Tilting roller system for folding a pneumatic tyre carcass insert around a bead core and folding-up method
Publication Date: 2025.08.06 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4363207B1 patent drawingFigure 1~2
  • EP4363207B1 patent drawingFigure 3~4
  • EP4363207B1 patent drawingFigure 5

AI summary

The invention relates to a folding-up system intended to fold an end section (3A, 3B) of a cylindrical wall (3) of a tyre carcass assembly (2) around a reinforcing bead core (4, 5), the system comprising a drive device (20) arranged to intermittently rotate the carcass assembly (2) around its roll axis (X3), according to successive angular increments, as well as a folding-up device (10) for causing the pressure rollers (11, 12, 13) to tilt, after each angular roll increment, around a pitch axis (Y30) perpendicular to the roll axis (X3), so as to fold the radially inner face (3_in) of the wall around the reinforcing bead core (4, 5).