Fuel Bladder Flange Locking for Leak-Tight Tank Assembly

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Solution Overview

Problem

Existing fuel tank connection systems in aerospace and other fields require time-consuming assembly, risk damage during screwing and unscrewing, and suffer from variability due to operator dependence and reduced clamping force over time, along with maintenance challenges from stuck flexible chimneys.

Innovation Solution

A fuel tank communication system with two independent locking features, including a notched ring and spring mechanism, and a lock ring, that securely connects fuel bladders without requiring access to both tanks, using a main body with a seal portion and securement features like C-clips, and materials like lightweight metals or high-performance thermoplastics for leak-tight and crashworthy connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal clamps are secured via screwdriver, then the flexible chimneys can be connected between tanks, but the assembly process takes time and risks damaging the tanks or chimneys due to constant pressure from screwing and unscrewing

Engineering Contradiction:
Improveconnection reliabilityVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces the screwdriver-based mechanical fastening system with a cam-actuated locking mechanism. The cam lever (44) engages with locking surfaces (48, 52) to secure the flexible chimney, eliminating the need for screwing operations. This substitution maintains connection reliability while dramatically improving assembly ease by removing the need for rotational tightening operations that risk damage.

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

Solution Approach 2:

The cam-actuated mechanism provides self-locking functionality where the cam lever (44) automatically engages with the locking surfaces (48, 52) when actuated, creating a self-securing connection. The spring (46) provides automatic return and engagement force, making the connection process self-completing without requiring precise operator control of screw tightening force.

Inventive Principle:
Principle #25Self-service

2Reliability

If metal clamps are used to fix tanks, then the flexible chimneys can be connected, but the clamping force decreases over time and rubber aging causes the chimneys to stick together under the clamps

Engineering Contradiction:
Improveconnection reliabilityVSAvoidconnection duration
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the screw-based metal clamp system with a cam-actuated locking mechanism. The cam lever (44) creates a concentrated locking force at specific points (locking surfaces 48, 52) rather than distributed clamping pressure. This substitution prevents rubber aging-related sticking by eliminating broad contact areas under compression, while the localized locking points maintain connection reliability over extended durations.

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

3Reliability

If screwdriver-based metal clamps are used, then the flexible chimneys can be secured, but operator competence and strength create variability in the connection quality

Engineering Contradiction:
Improveconnection reliabilityVSAvoidoperator dependence
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The cam-actuated mechanism with spring (46) provides automatic engagement and locking force application. When the cam lever (44) is actuated, the spring automatically provides the necessary engagement force, eliminating variability from operator strength differences. The geometric locking action ensures consistent connection quality regardless of operator competence, as the mechanism itself enforces proper engagement.

Inventive Principle:
Principle #25Self-service

4Ease of repair

If disassembly is performed on stuck flexible chimneys under metal clamps, then the connection can be broken, but the process is difficult and adds to maintenance issues

Engineering Contradiction:
Improvedisassembly easeVSAvoidconnection stability
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The patent replaces the screw-based metal clamp system with a cam-actuated locking mechanism. The cam lever (44) can be easily actuated to release the locking engagement with surfaces (48, 52), providing simple disassembly without requiring unscrewing operations. This maintains connection stability during operation while enabling easy maintenance disassembly, directly addressing the stuck chimney problem by eliminating continuous clamping pressure that causes adhesion.

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

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

Facilitates quick, tool-free assembly and disassembly of fuel tanks with reduced risk of damage, maintains secure connections, and minimizes maintenance issues by providing reliable, leak-tight, and crashworthy interconnections that meet aerospace standards.

Implementation Method 1

A first locking system (40) features a notched ring (42) and a spring (44)

Methodology Applied
Scientific EffectSpring mechanism: Spring

Data Source

PatentEP3652070B1Fuel tank communication systems
Publication Date: 2023.05.17 SAFRAN AEROSYST
  • EP3652070B1 patent drawingFigure 1~2
  • EP3652070B1 patent drawingFigure 3~4
  • EP3652070B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention provide a fuel tank communication system. The communication system includes a main body (30) used to connect two fuel bladder flanges (12, 20) to one another. The communication system provides two separate, independent locking features (42, 60) that can secure fuel bladders to one another.