Rotating Harness Collar for Aircraft Clamp Chafing Reduction

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Solution Overview

Problem

Aircraft harnesses in anti-ice systems suffer from repetitive stress and torsional forces at clamping points, leading to damage, cutting, chafing, and eventual system failure, typically occurring around 3000 flight hours or 2000 flight cycles.

Innovation Solution

A fastening system for aircraft harnesses that includes a collar or bobbin inserted into an existing clamp, allowing the harness to rotate and reducing friction, thereby minimizing damage from torsional forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the harness is clamped directly to the clamp, then the harness is securely held in place, but the harness suffers from repetitive stress, torsional forces, friction, and damage leading to premature failure

Engineering Contradiction:
Improveharness lifespanVSAvoidtorsional force and friction damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a collar as an intermediary component between the clamp and the harness. The collar rotates within the clamp, serving as a mediator that absorbs torsional forces and reduces friction on the harness. This allows the harness to move and rotate freely within the collar without direct contact with the clamp, eliminating the harmful torsional stresses while maintaining secure positioning.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The collar is designed to rotate dynamically within the clamp, transforming the static clamping arrangement into a dynamic system. This rotation capability allows the collar to accommodate movements and torsional forces without transmitting them to the harness, thereby protecting the harness from damage while maintaining connection integrity.

Inventive Principle:
Principle #15Dynamics

2Strength

If the clamp is made rigid to securely hold the harness, then the harness is firmly positioned, but the rigidity causes increased friction and torsional stress on the harness during movement

Engineering Contradiction:
Improveclamp holding strengthVSAvoidfriction and chafing
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The collar acts as a intermediary element that decouples the rigid clamp from the flexible harness. The clamp maintains its rigid structure for secure mounting, while the collar provides a rotating interface that reduces friction and prevents direct contact between the clamp and harness, thereby eliminating chafing and excessive friction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The collar is designed with a cylindrical hollow structure that allows the harness to move freely within it. This shell-like structure accommodates harness movement without transmitting rigid constraints, reducing friction and preventing chafing while maintaining the holding strength of the rigid clamp.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If the clamp directly secures the harness, then the installation is simple, but the harness experiences concentrated stress at the clamping point causing damage after approximately 3000 flight hours or 2000 flight cycles

Engineering Contradiction:
Improveclamping system simplicityVSAvoidharness durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The clamping system is segmented into three distinct components: the clamp, the collar, and the harness. This segmentation allows each component to perform its specific function - the clamp provides secure mounting, the collar provides rotational movement and stress absorption, and the harness carries the electrical connections. This division protects the harness from concentrated stress while maintaining installation simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The collar serves as an intermediary component that distributes and absorbs stress away from the harness. By placing the collar between the clamp and harness, the system protects the harness from concentrated stress at the clamping point, thereby extending durability without significantly increasing complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system effectively reduces damage to aircraft harnesses by distributing torsional forces and minimizing friction, thereby extending the lifespan of the harnesses and preventing system failures.

Implementation Method 1

allowing the harness to rotate and reducing friction, thereby minimizing damage from torsional forces

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4151520B1Aircraft line or harness fastening system
Publication Date: 2025.04.02 AIRBUS CANADA LLP
  • EP4151520B1 patent drawingFigure 1A~1B
  • EP4151520B1 patent drawingFigure 1C
  • EP4151520B1 patent drawingFigure 2~3

AI summary

In an aircraft line or harness fastening system (32), a clamp (2) attaches a line or harness (30) to an aircraft. A collar (1) within the clamp surrounds the line or harness (30). The collar (1) is smaller than the clamp (2) and is circular in shape to enable rotation of the collar (11) within the clamp (2). The collar (1) comprises two separate complementary parts that fit together around the line or harness (30). Each of the two separate complementary parts includes a tab and a recess. The tab of one of the complementary parts fits into the recess on the other of the complementary parts.