Flexible Metatarsal Guard Using Composite Layers

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional metatarsal guards are rigid, unsightly, and limit foot motion due to their external and bulky design, failing to provide adequate protection and comfort for the metatarsal region of the foot.

Innovation Solution

A metatarsal guard comprising a base layer, an elastomeric polyurethane foam layer, and a puncture-resistant woven fibrous layer, molded together to create a flexible and impact-absorbing product that can be integrated into safety shoes or boots, enhancing protection and comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid synthetic plastic or metal shield is used to protect the metatarsal region, then protection against impact and crushing forces is improved, but flexibility and range of motion of the foot deteriorate

Engineering Contradiction:

Improveprotection against impact and crushing forcesVSAvoidrange of motion of the foot

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The patent replaces rigid shields with a flexible elastomeric material that forms a thin film or shell structure. This flexible material conforms to the foot's natural movement while providing protective coverage to the metatarsal region, eliminating the restriction on foot motion caused by rigid barriers.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs composite material construction combining multiple layers including elastomeric materials with varying degrees of rigidity and flexibility. This layered composite structure provides impact protection through harder outer layers while maintaining overall flexibility through softer inner layers, resolving the contradiction between strength and flexibility.

Inventive Principle:

Principle #40Composite materials

2Strength

If a rigid metatarsal shield is placed externally on the shoe, then protection against falling objects is improved, but the appearance and comfort of the footwear deteriorate

Engineering Contradiction:

Improveprotection against falling objectsVSAvoidappearance and bulkiness of the shoe

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The protective metatarsal guard is nested within the footwear structure, specifically positioned inside the tongue or upper portion of the shoe. This nesting approach allows the protective element to be concealed within the shoe's existing form, eliminating the unsightly external appearance and bulkiness associated with external shields while maintaining protection against falling objects.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The use of flexible elastomeric material allows the protective layer to be made thin and conformable, enabling it to be integrated into the shoe's internal structure without adding significant bulk or distorting the shoe's external shape, thus maintaining aesthetic appearance while providing protection.

Inventive Principle:

Principle #30Flexible shells and thin films

3Strength

If a rigid metatarsal shield is used, then protection against puncture forces is improved, but flexibility and comfort of the footwear deteriorate

Engineering Contradiction:

Improveprotection against puncture forcesVSAvoidflexibility and comfort

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The patent uses composite material construction with multiple layers having different properties. The outer layers provide puncture resistance through tougher materials, while inner layers maintain flexibility and comfort against the foot. This layered composite approach allows simultaneous achievement of puncture protection and flexibility that single-material solutions cannot provide.

Inventive Principle:

Principle #40Composite materials

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 solution provides improved flexibility, impact absorption, and puncture resistance, making the metatarsal guard more comfortable and effective in preventing injuries while maintaining the appearance and functionality of standard footwear.

Implementation Method 1

an elastomeric polyurethane foam layer on the base layer

Methodology Applied

Scientific EffectImpact absorption: Deformation

Implementation Method 2

a puncture resistant layer on the elastomer foam layer on a side opposite the base layer

Methodology Applied

Scientific EffectPuncture resistance: Friction

Data Source

PatentUS20240324716A1Puncture resistant flexible metatarsal guard

Publication Date: 2024.10.03 ROGERS CORP

AI summary

A metatarsal guard includes a base layer, an elastomeric polyurethane foam layer on the base layer, and a puncture resistant layer on the elastomer foam layer on a side opposite the base layer. Advantageously, the metatarsal guard is flexible and capable of providing top-of-foot protection to the metatarsal region of a foot. The metatarsal guard is formed by a molding process. A safety shoe or boot having improved protection for the metatarsal region of a wearer's foot is also disclosed.