Unreinforced Elastomeric Spring Wall with Variable Stiffness Profile

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Solution Overview

Problem

Conventional gas spring devices face challenges in reducing manufacturing costs and suffer from issues like increased wear and heat retention due to external reinforcement, which limits their application and effectiveness.

Innovation Solution

The development of unreinforced elastomeric spring walls with varying stiffness profiles along their longitudinal length, achieved through differences in material properties and geometry, eliminates the need for internal and external reinforcement, thereby reducing manufacturing costs and improving performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If internal reinforcement (filaments or cords) is embedded in the spring wall, then the strength and pressure resistance of the spring wall is improved, but the manufacturing complexity and cost increase due to multiple fabrication steps

Engineering Contradiction:
Improvespring wall strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention extracts and removes the reinforcement filaments or cords from the spring wall construction, eliminating the need for complex embedding processes while maintaining spring wall integrity through alternative design approaches

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention applies local quality by varying the thickness of the elastomeric material at different locations of the spring wall, creating regions of different stiffness that provide both strength where needed and flexibility where required, without requiring internal reinforcement

Inventive Principle:
Principle #3Local quality

2Strength

If external reinforcement structures (coil spring or restraining cylinder) are used, then the pressure resistance and structural support are improved, but the manufacturing cost increases due to additional components and assembly steps

Engineering Contradiction:
Improvepressure resistanceVSAvoidcomponent quantity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention removes external reinforcement structures such as coil springs and restraining cylinders, achieving pressure resistance through the inherent properties of the elastomeric material itself rather than through additional supporting components

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the functions of the spring wall and reinforcement structures into a single integrated elastomeric component, where the variable thickness design simultaneously provides both structural support and pressure resistance that were previously requiring separate components

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If external reinforcement components are used, then the structural support is improved, but the wear and heat retention increase, limiting application suitability

Engineering Contradiction:
Improvestructural supportVSAvoidwear and heat retention
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention extracts external reinforcement components that cause wear and heat retention issues, eliminating these harmful effects while maintaining structural support through the elastomeric material's inherent properties

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The variable thickness design creates local regions with optimized properties, allowing the spring wall to provide structural support where needed while maintaining lower wear and heat retention characteristics throughout the elastomeric material compared to composite constructions

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

This solution enables gas spring assemblies with optimized performance characteristics, such as increased hoop strength and improved fatigue life, while reducing manufacturing costs and minimizing wear and heat retention, thus expanding the suitability of gas spring devices across various applications.

Implementation Method 1

The spring wall of a conventional gas spring device is adapted to flex during dynamic operation and use of the gas spring device and is therefore normally made from a flexible, elastomeric material

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2351946B1Unreinforced elastomeric spring wall, gas spring and method
Publication Date: 2019.11.27 FIRESTONE INDUSTRIAL PRODUCTS COMPANY LLC
  • EP2351946B1 patent drawingFigure 1
  • EP2351946B1 patent drawingFigure 2~3
  • EP2351946B1 patent drawingFigure 4

AI summary

A spring wall for securement between associated end members for forming an associated gas spring assembly includes a first wall portion that extends axially along a longitudinal axis and circumferentially thereabout. The first wall portion is formed from an unreinforced elastomeric material, and the first wall portion has a first nominal stiffness value. A second wall portion extends along the longitudinal axis and circumferentially thereabout. The second wall portion is disposed in longitudinal relation to the first wall portion and has a second nominal stiffness value that is different from the first nominal stiffness value of the first wall portion such that a non-constant stiffness profile is established along a longitudinal length of the spring wall. A gas spring and a gas spring and reservoir assembly utilizing such a spring wall as well as a method of manufacturing a gas spring are also included.