Variable-Shape Auxiliary Drum for Uniform Tyre Belt Shaping

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Solution Overview

Problem

The shaping of belt layers in ultra-high performance tyres, particularly for race car competitions, is hindered by increased structural rigidity and non-uniform expansion, leading to uncontrolled deformations and material selection limitations, which affect the control of the footprint area and overall performance.

Innovation Solution

A process involving the turning-up of the flaps of the first belt layer after shaping the annular assembly, combined with the use of a first auxiliary drum with variable shape and switching members, allows for uniform expansion and selection of materials with desired mechanical characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional tyre building machines are used, then the construction of tyre carcasses and bead assemblies is possible, but the process requires separate machines for different tyre components and multiple manual operations

Engineering Contradiction:
Improvetyre building efficiencyVSAvoidnumber of separate machines
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple separate tyre building machines into a single integrated machine that can construct both the carcass assembly and bead assembly in one continuous operation. The integrated machine includes a first workstation for carcass construction and a second workstation for bead assembly, both controlled from a central location, eliminating the need for separate machines and manual transfer operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated tyre building machine performs multiple functions that previously required separate specialized machines. It can construct the carcass assembly, construct the bead assembly, and apply different types of compounds (bulk compound and tread compound) all through a single machine system, making the equipment universal for various tyre building operations.

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

2Ease of manufacture

If separate machines are used for carcass and bead assembly, then each machine can be optimized for its specific function, but the overall process requires more floor space and coordination

Engineering Contradiction:
Improvespecialization of equipmentVSAvoidfloor space requirement
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent merges the carcass building function and bead assembly function into a single integrated machine footprint. The first and second workstations are positioned adjacent to each other within the same machine structure, allowing both functions to share the same floor space rather than requiring separate machine locations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bead assembly workstation is integrated within the overall structure of the tyre building machine, with the second bead assembly tool positioned to work in conjunction with the first carcass building tool. The components and tools are nested within a compact arrangement that minimizes the external footprint while maintaining functional separation.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of operation

If manual operations are used for tyre building, then flexibility in operation is maintained, but construction time and labour intensity increase

Engineering Contradiction:
Improveoperational flexibilityVSAvoidconstruction time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system prepares materials and positions tools in advance for each construction step. The compound delivery system pre-positiones compound reservoirs and delivery mechanisms, while the bead assembly tool pre-positions the bead core and surrounding tools before the actual assembly operation begins, reducing construction time without sacrificing operational flexibility.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The integrated machine enables continuous operation where the bead assembly process can begin while the carcass is still being constructed. The first and second workstations operate in a coordinated continuous manner, eliminating idle time between operations and maintaining continuous useful action throughout the tyre building process.

Inventive Principle:
Principle #20Continuity of useful action

4Device complexity

If traditional compound application methods are used, then simple equipment is required, but compound distribution uniformity and tyre quality suffer

Engineering Contradiction:
Improvecompound delivery systemVSAvoidcompound distribution uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The compound delivery system is integrated into the tyre building machine and serves multiple functions: it delivers bulk compound to the carcass, delivers tread compound to the bead assembly, and provides controlled distribution in both cases. This multi-functional system achieves precise compound distribution while being part of the unified machine structure.

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

Solution Approach 2:

The control system monitors the compound application process and adjusts delivery parameters to ensure uniform distribution. The centralized control location coordinates compound delivery timing and quantity based on the construction progress, providing feedback control that maintains manufacturing precision without requiring overly complex mechanical delivery mechanisms.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4452612B1Process and plant for building tyres for vehicle wheels
Publication Date: 2026.04.29 PIRELLI TYRE SPA
  • EP4452612B1 patent drawingFigure 1
  • EP4452612B1 patent drawingFigure 2
  • EP4452612B1 patent drawingFigure 3

AI summary

A plant (1) for building tyres (2) for vehicle wheels comprises a carcass structure building line (13), a crown structure building line (14) and an assembly station (15). The crown structure building line (14) comprises a first auxiliary drum (22) having shape variable between a cylindrical shape and a toroidal shape and comprising turning-up members (54). The plant implements a process in which an annular assembly (A) made on the first auxiliary drum (22) is shaped and subsequently subjected to a turning-up action while it is associated with the first auxiliary drum (22).