Overmolded Spectacle Arm Extremities for Eyewear

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Solution Overview

Problem

Existing protective eyewear for military and law-enforcement personnel lacks durable and cost-effective ear stem or temple pads that prevent irritation and scratching of the lens when folded for storage.

Innovation Solution

An ear stem or temple design featuring a hard base structure made of NYLON with a soft, thermoplastic elastomer pad overmolded onto the base, providing a secure and rugged attachment through anchor portions and geometry, preventing irritation and lens scratching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a hard material is used for the ear stem base structure, then durability and structural integrity are improved, but comfort and prevention of irritation deteriorate

Engineering Contradiction:

Improvestructural integrityVSAvoidirritation

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The ear stem is designed with different materials for different portions: a hard base structure for structural integrity and a soft pad portion for comfort. This local differentiation of material properties resolves the contradiction between durability and irritation prevention.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The ear stem combines two different materials (hard base material and soft pad material) into a single composite structure, allowing each material to perform its optimal function - the hard material provides strength while the soft material prevents irritation.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If a soft pad material is used for the ear stem pad, then comfort and irritation prevention are improved, but attachment security and resistance to removal deteriorate

Engineering Contradiction:

ImproveirritationVSAvoidattachment security

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The soft pad portion and base structure are merged into a single integrated component through overmolding, ensuring that the soft pad cannot be easily removed while maintaining its comfort properties. The anchor portions further combine the two materials securely.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The composite structure of hard base material and soft pad material is permanently bonded through overmolding and anchor portions, achieving both comfort and secure attachment simultaneously.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If conventional attachment methods are used for the ear stem pad, then manufacturing simplicity is maintained, but durability and resistance to harsh conditions deteriorate

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoiddurability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The soft pad portion is overmolded onto the base structure during the manufacturing process, creating a permanent bond before the product is put into service. This preliminary attachment action ensures durability while maintaining manufacturing efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The overmolding process creates a composite material structure where the soft pad and hard base are chemically and mechanically bonded, providing superior durability compared to conventional attachment methods while remaining cost-effective.

Inventive Principle:

Principle #40Composite materials

4Ease of operation

If the eyewear is folded for storage with hard stem tips, then storage convenience is improved, but scratching of the lens deteriorate

Engineering Contradiction:

Improvestorage convenienceVSAvoidscratching

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The tip ends of the ear stems are covered with soft pad material, creating a local soft covering that prevents scratching when the eyewear is folded for storage, while the rest of the stem maintains its hard structural properties.

Inventive Principle:

Principle #3Local quality

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 offers a durable and cost-effective attachment of soft pads to eyewear stems, preventing irritation and lens scratching, while maintaining secure attachment under harsh conditions.

Implementation Method 1

a soft pad portion composed of a relatively softer and/or more resilient material that is overmolded onto the base structure

Methodology Applied

Scientific EffectOvermolding:

Implementation Method 2

The soft portion is not only overmolded onto the harder stem base structure, but is also anchored by the interacting geometry of the two molded components to form both a chemical and a mechanical fixation

Methodology Applied

Scientific EffectMechanical fixation: Mechanical Fastener

Data Source

PatentUS7490935B1Overmolded spectacle arm extremities

Publication Date: 2009.02.17 REYEWEAR ACQUISITION INC

AI summary

A stem for eyewear includes an elongated base configured for support on a user's ear and comprising a relatively hard material and a soft pad portion overmolded onto the elongated base. The base comprises at least one through hole and the soft pad portion comprises an anchor portion that is continuous through the through hole. The base also includes an anchor loop on an end that is covered and penetrated by the soft pad portion.