Fluid-Filled EVA Suit Joint Assembly for Constant-Volume Articulation

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Solution Overview

Problem

Conventional EVA suit joints experience significant volume changes during articulation, requiring excessive energy and effort from users due to pressure differences, limiting time in low-pressure environments and increasing resource consumption.

Innovation Solution

A joint assembly with a flexible bladder and reinforcing fibers that maintains a constant internal volume through articulation, using a non-gaseous fluid and self-healing properties to prevent rupture and enhance tensile strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the joint is articulated in a conventional EVA suit, then the joint can bend and move, but the volume inside the joint changes causing significant energy consumption and user fatigue

Engineering Contradiction:
Improveease of joint articulationVSAvoidenergy consumption during joint movement
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent changes the physical state of the fluid from gaseous to non-gaseous (liquid or gel), which fundamentally alters the compressibility characteristics. This parameter change allows the joint to maintain constant volume while articulating, eliminating the energy-consuming volume expansion/contraction cycle that occurs with gaseous fluids.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional mechanical bellows structure with a fluid-filled bladder system. This substitution eliminates the need for complex mechanical expansion and contraction mechanisms, reducing moving parts and potential failure points while maintaining joint articulation capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Use of energy by moving object

If the EVA suit is pressurised at low pressure (3-4 PSI) to reduce the work required for joint movement, then energy consumption decreases, but oxygen resources are overused and time in space is still limited

Engineering Contradiction:
Improveenergy consumption for joint movementVSAvoidoxygen consumption
Core Design Contradiction:
Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The patent changes the pressure parameter from low (3-4 PSI) to higher pressures that can sustain 1 atmosphere inside the EVA suit. This is made possible by the constant-volume joint design, which eliminates the energy penalty for joint articulation, thereby allowing normal atmospheric pressure without excessive oxygen consumption.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a bellows structure is used for the joint, then joint articulation is enabled, but the structure is complex and may not maintain constant volume effectively

Engineering Contradiction:
Improvejoint articulation capabilityVSAvoidstructural complexity of joint assembly
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical bellows structure with a simpler fluid-filled bladder system. The bladder with non-gaseous fluid provides the necessary volume maintenance through fluid incompressibility, eliminating the complex folded sheet material structure of traditional bellows while maintaining joint articulation capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses hydraulic principles by filling the bladder with non-gaseous fluid (liquid or gel). This hydraulic approach provides inherent volume constancy through fluid incompressibility, replacing the mechanical bellows structure with a simpler pressure-based volume control mechanism.

Inventive Principle:
Principle #29Pneumatics and hydraulics

4Ease of operation

If the joint volume changes during articulation, then joint movement is possible, but this causes significant stress on the user and limits time in the EVA suit

Engineering Contradiction:
Improvejoint mobilityVSAvoidduration of time in EVA suit
Core Design Contradiction:
Ease of operationVSDuration of action of moving object

Solution Approach 1:

The patent changes the compressibility parameter of the joint fluid from compressible (gaseous) to incompressible (non-gaseous liquid or gel). This parameter change enables the joint to maintain constant volume during articulation, eliminating the energy-consuming volume changes that limit user duration in the EVA suit.

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

Reduces the effort required to maneuver in EVA suits, allowing longer durations in low-pressure environments while minimizing resource use and preventing catastrophic failures.

Implementation Method 1

The chamber is partially filled with a non-gaseous fluid which moves within the chamber during articulation of the tubular body

Methodology Applied
Scientific EffectIncompressibility of non-gaseous fluid:

Implementation Method 2

The membrane comprises a plurality of reinforcing fibres arranged to prevent the membrane from expanding or stretching

Methodology Applied
Scientific EffectReinforcement:

Implementation Method 3

self-healing properties to prevent rupture and enhance tensile strength

Methodology Applied
Scientific EffectSelf-healing:

Data Source

PatentEP4526213B1Joint assembly
Publication Date: 2026.04.22 LONSDALE TECHNOLOGIES LTD
  • EP4526213B1 patent drawingFigure 1A~1B
  • EP4526213B1 patent drawingFigure 1C~1D
  • EP4526213B1 patent drawingFigure 2A~2C

AI summary

The present disclosure relates to a joint assembly configured to define a tubular body having a first end, a second end and a passage therebetween. The tubular body is configured for articulation between a first state in which the first end and second end are in a first orientation with respect to one another, and a second state in which the first end and second end are in a second orientation with respect to one another. The body comprises a flexible bladder arranged between opposing supports, each of the bladder and the supports being ring-shaped so as to define an aperture, the respective apertures forming part of the passage. The bladder defines a chamber, and the chamber is partially filled with a fluid which moves within the chamber during articulation of the tubular body from said first state to said second state in order to maintain a constant internal volume of the joint assembly.