Offset Zigzag Belt Structure for Pneumatic Tires

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Solution Overview

Problem

Conventional pneumatic tires face issues with cracks in the belt layers, leading to sudden cuts and peeling off, particularly due to radial growth at high speeds, which existing zigzag and spirally wound belt structures fail to adequately address.

Innovation Solution

The tire features two zigzag belt layers with cords inclined at specific angles, sandwiched between a circumferentially spirally wound layer, where the first and second zigzag layers have different cord angles and are formed from a continuous strip, reducing radial growth and stress concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional zigzag belt layers are used with progressive cord angle increases, then the belt structure provides stiffness in the crown area, but cracks develop inside the belt layers leading to sudden cuts and peeling off

Engineering Contradiction:
Improvebelt structure strengthVSAvoidbelt layer integrity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies local quality by creating an extra laminated portion at specific locations (side end portions between adjoining inner zigzag belt plies) with different structural characteristics. This localized reinforcement with different cord arrangement and lamination pattern addresses the specific vulnerability area without altering the entire belt structure, preventing crack initiation and propagation at these critical locations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining multiple belt plies with different cord angles and orientations (inner zigzag belt plies with outer zigzag belt plies having different cord angles). The extra laminated portion creates a composite structure that integrates materials with different mechanical properties, enhancing overall belt layer integrity and resistance to crack development.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If extra laminated portions are added to increase circumferential rigidity at lateral edges, then radial growth during high speed running is reduced, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecircumferential rigidityVSAvoidbelt structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the belt structure into distinct functional zones: inner zigzag belt plies, outer zigzag belt plies with different cord angles, and extra laminated portions at specific locations. This segmentation allows each zone to perform its specific function - the extra laminated portions specifically address circumferential rigidity at lateral edges without requiring complete redesign of the entire belt structure.

Inventive Principle:
Principle #1Segmentation

3Force

If multiple belt plies are sandwiched together to stiffen the crown area, then the tire provides structural support, but stress concentrations develop leading to radial growth and tread cracking

Engineering Contradiction:
Improvestructural support forceVSAvoidstress concentration
Core Design Contradiction:
ForceVSStress or pressure

Solution Approach 1:

The patent applies preliminary action by incorporating the extra laminated portion at the side end portions before operational stresses can cause damage. This pre-reinforcement structure proactively mitigates stress concentrations that would otherwise develop during high-speed running and heavy load conditions, preventing crack initiation before it occurs.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2202094B1Offset zigzag belt structure for a pneumatic tire
Publication Date: 2013.01.16 THE GOODYEAR TIRE & RUBBER CO
  • EP2202094B1 patent drawingFigure 1
  • EP2202094B1 patent drawingFigure 2
  • EP2202094B1 patent drawingFigure 3

AI summary

A pneumatic tire (10) such as a radial truck tire is described. The tire (10) has a carcass (31) and a belt reinforcing structure (40), the belt reinforcing structure (40) comprising a first zigzag belt layer (41) having a first amplitude or layer width and a first wavelength and a second zigzag belt layer (42) having a second amplitude or layer width and a second wavelength, the first wavelength of the first zigzag layer (41) being out of phase with the second wavelength of the second zigzag layer (42).