Shoe Outsole Tread Pattern for Slip Resistance

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Solution Overview

Problem

Existing shoe tread designs fail to adequately address the varying needs of different foot strike phases during walking on slick surfaces, leading to slipping and falling, particularly on wet, icy, or greasy floors, as they do not account for the distinct traction requirements of heel, mid, and forefoot areas.

Innovation Solution

A combination tread pattern for shoe outsoles featuring a heel strike tread with a pointed front end and siping for liquid channeling, and cross-siped treads for the forefoot area to enhance traction, utilizing a slip-resistant polymeric material that conforms to the ground surface, with the heel tread acting like a squeegee to prevent forward slippage and the forefoot treads providing side directional traction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a uniform tread pattern is used across the entire outsole, then the shoe structure is simple and easy to manufacture, but it fails to provide adequate traction on slick surfaces during different phases of walking

Engineering Contradiction:
Improvetraction on slick surfacesVSAvoidtread pattern complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The outsole is divided into three distinct tread patterns corresponding to heel, midfoot, and forefoot areas. Each segment addresses specific traction needs during different phases of the walking gait cycle, with the heel strike tread having a pointed front end for penetrating slippery surfaces, the midfoot tread providing lateral stability, and the forefoot tread offering push-off traction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the outsole are equipped with tread patterns having different geometries and functions tailored to local requirements. The heel area receives a pattern optimized for initial contact and stopping, the midfoot for lateral support, and the forefoot for propulsive force, ensuring each region performs its specific function optimally.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the tread material is made harder to resist deformation, then the tread maintains its shape better, but it reduces the ability to conform to the ground surface and adhere

Engineering Contradiction:
Improvetread shape stabilityVSAvoidadhesion to ground surface
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The tread material's durometer is specifically adjusted to fall within the range of 40-60 Shore A, optimizing the balance between maintaining structural integrity and conforming to ground surfaces. This parameter optimization allows the tread to resist excessive deformation while still adapting to surface irregularities for maximum contact and adhesion.

Inventive Principle:
Principle #35Parameter changes

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 tread combination effectively reduces slipping by channeling liquids away from the contact surface and providing superior grip, ensuring stability and balance on wet and greasy surfaces, with a slip resistance rating of 0.56 - 0.65 on the Brungraber Mark 2 Articulated Strut Slip Testing Device.

Implementation Method 1

siping for channeling liquid away from the contact surface

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

siping for channeling liquid away from the contact surface

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 3

the siping allows the polymeric material of the tread to function with the surface as a softer durometer material than it actually is by flexing along the sipes

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 4

Efforts have also been made to coordinate the design of the sole with the anatomic variations of the foot... Enhanced gripping is based primarily on the configurations of the various projections, ridges, etc

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3413740A1Tread pattern combination for non-slip shoes
Publication Date: 2018.12.19 SHOES FOR CREWS INC

AI summary

The invention involves a tread system for shoes. More specifically, the present invention is a tread combination that is particularly suited to work environments where the workers are required to use a walking gait upon slick floor surfaces, some of which may be partially covered with liquids. The system includes an outsole having a heel strike tread having a pointed leading edge with sipes for squeegeeing and channeling liquid away from the center portion of the tread to prevent forward slippage. The mid and forefoot portions of the outsole are provided with cross siped treads which reduce or prevent sideways slippage of the forefoot.