Shoulder Block Tread Structure for Deep Snow Tire Traction

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Solution Overview

Problem

Existing tires experience insufficient traction and running performance on deep snow road surfaces due to inadequate design features.

Innovation Solution

The tire design includes a tread portion with specific block configurations and grooves that enhance snow compression and shearing, featuring angled second tread surfaces, lateral grooves, and varying rubber hardness to improve traction and reduce wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a side protector is raised outward in the tire axial direction, then running stability on off-the-road surfaces is improved, but traction on deep snow road surfaces becomes insufficient

Engineering Contradiction:
Improverunning stabilityVSAvoidtraction
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The shoulder block is divided into multiple surfaces (first tread surface, second tread surface, first side surface) with different functions. The second tread surface specifically addresses snow traction while other surfaces maintain stability, resolving the contradiction through functional segmentation of the block structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different surfaces of the shoulder block have different local properties: the second tread surface has a specific angle (10° or less) and grooves for snow traction, while other surfaces maintain structural integrity. This local differentiation allows simultaneous achievement of stability and snow traction.

Inventive Principle:
Principle #3Local quality

2Reliability

If the second tread surface extends at a small angle relative to the contact line, then snow compression capability is improved, but the complexity of the tread design increases

Engineering Contradiction:
Improvesnow compression capabilityVSAvoidtread design complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The angle of the second tread surface is optimized to 10° or less relative to the contact line, and the length ratio is set to 18-23% of the first tread surface. These specific parameter values achieve effective snow compression while maintaining manufacturable design complexity.

Inventive Principle:
Principle #35Parameter changes

3Force

If grooves are disposed in the second tread surface, then traction on deep snow is enhanced, but wear resistance of the tread surface may be reduced

Engineering Contradiction:
ImprovetractionVSAvoidwear resistance
Core Design Contradiction:
ForceVSStrength

Solution Approach 1:

Grooves are placed only in the second tread surface which has specific angular and dimensional characteristics, while other surfaces maintain solid structure for wear resistance. This localized groove placement provides snow traction where needed without compromising overall tread durability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4549172B1tire
Publication Date: 2026.03.04 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4549172B1 patent drawingFigure 1
  • EP4549172B1 patent drawingFigure 2
  • EP4549172B1 patent drawingFigure 3

AI summary

A tire that allows enhancement of running performance on a deep snow road surface is provided. A tire 1 includes a first shoulder block 3. The first shoulder block 3 includes a first tread surface 5 extending inward from a first tread end T1 in the tire axial direction, a first side surface 6 extending inward from the first tread end T1 in the tire radial direction, and a second tread surface 7 extending outward from the first side surface 6 in the tire axial direction. The second tread surface 7 extends at an angle θ of 10° or less relative to a contact line 5n extending in contact with the first tread surface 5 through the first tread end T1. At least one groove 8 is disposed in the second tread surface 7.