Winter Tyre Sipe Geometry for Stiffness and Snow Retention

Solution Overview

Problem

Winter tyres with complex type sipes improve stiffness on dry and wet surfaces but compromise snow retention and manufacturing complexity.

Innovation Solution

A tyre design featuring complex type sipes with alternating recesses and protrusions on block surfaces, optimizing stiffness without hindering snow retention and manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex type sipes are provided on the blocks, then the tyre performance on dry or wet road surfaces is improved, but the manufacturing complexity increases and the ability to retain snow is reduced

Engineering Contradiction:

Improvetyre performance on dry or wet road surfacesVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by providing complex type sipes only on specific blocks (first and second blocks) while leaving other blocks (third and fourth blocks) without such sipes. This selective application optimizes tyre performance on dry or wet surfaces in the regions where complex sipes are provided, while avoiding the manufacturing complexity and snow retention issues that would arise from applying complex sipes across the entire tread band.

Inventive Principle:

Principle #3Local quality

2Reliability

If complex type sipes are provided on the blocks, then the tyre performance on dry or wet road surfaces is improved, but the ability to retain snow is reduced

Engineering Contradiction:

Improvetyre performance on dry or wet road surfacesVSAvoidsnow retention ability

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing complex type sipes only on specific blocks (first and second blocks) while leaving other blocks (third and fourth blocks) without such sipes. This selective application optimizes tyre performance on dry or wet surfaces in the regions where complex sipes are provided, while avoiding the manufacturing complexity and snow retention issues that would arise from applying complex sipes across the entire tread band.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12479243B2Winter tyre

Publication Date: 2025.11.25 PIRELLI TYRE SPA

AI summary

A tyre includes at least one block on which at least one complex type sipe is obtained separating the block into two portions having a first surface and a second surface facing each other. The first surface is extended between a set of first and second longitudinal sections having, respectively, a first and a second radial profile, which are symmetrical to each other, each one comprising a coupling portion between the two block portions formed by a protrusion and a recess defined by three consecutive inclined lengths, the pattern of which is such that the ends of the coupling portion are offset from each other along a direction transverse to the longitudinal direction of the sipe.