Variable-Wall Seat Tubing for Even Load Distribution

Solution Overview

Problem

Aircraft seat tubes with constant wall thicknesses experience uneven force distribution and are heavy, requiring complex assembly and prone to decoupling during stress conditions like crash landings.

Innovation Solution

Tubular bodies with variable wall and outer diameters, made from materials like aluminum or steel via cold form drawing, distribute loads evenly and prevent decoupling by reinforcing stressed areas and providing a stable connection to frame components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If tubes are made with constant wall thickness, then manufacturing is simpler, but load distribution becomes uneven and weight increases

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidload distribution

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The tube employs variable wall thickness where the wall thickness varies along the length of the tube, being thinner in low-stress areas and thicker in high-stress areas. This local variation in geometry optimizes load distribution while maintaining manufacturing feasibility through cold form drawing processes.

Inventive Principle:

Principle #3Local quality

2Ease of manufacture

If tubes are made with constant wall thickness, then manufacturing is simpler, but tube weight increases

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidtube weight

Core Design Contradiction:

Ease of manufactureVSWeight of moving object

Solution Approach 1:

The tube employs variable wall thickness where the wall thickness varies along the length of the tube, being thinner in low-stress areas and thicker in high-stress areas. This local variation in geometry optimizes load distribution while maintaining manufacturing feasibility through cold form drawing processes.

Inventive Principle:

Principle #3Local quality

3Strength

If tubes have abrupt transitions in sidewall thickness, then reinforcement is achieved, but force distribution becomes uneven

Engineering Contradiction:

Improvelocal reinforcementVSAvoidforce distribution

Core Design Contradiction:

StrengthVSStress or pressure

Solution Approach 1:

The tube employs variable wall thickness where the wall thickness varies along the length of the tube, being thinner in low-stress areas and thicker in high-stress areas. This local variation in geometry optimizes load distribution while maintaining manufacturing feasibility through cold form drawing processes.

Inventive Principle:

Principle #35Parameter changes

4Weight of moving object

If complex tube configurations are used to reduce weight, then weight decreases, but assembly time increases

Engineering Contradiction:

Improvetube weightVSAvoidassembly time

Core Design Contradiction:

Weight of moving objectVSLoss of time

Solution Approach 1:

The invention integrates the reinforcement function directly into the tube wall structure through variable thickness, eliminating the need for separate reinforcement components. The variable wall thickness tube is manufactured as a single integrated component through cold form drawing, reducing assembly steps while maintaining structural integrity.

Inventive Principle:

Principle #5Merging (Combining)

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 achieves even load distribution, reduces weight, simplifies assembly, and enhances structural integrity by preventing decoupling during dynamic events, while maintaining strength and stiffness.

Implementation Method 1

distribute loads more evenly... distribute loads evenly... even load distribution

Methodology Applied

Scientific EffectStress distribution:

Implementation Method 2

made from a cold form drawing process

Methodology Applied

Scientific EffectCold form drawing: Cold-forming

Data Source

PatentUS8506015B2Vehicle seat tubing having variable wall thickness

Publication Date: 2013.08.13 SAFRAN CABIN INC

AI summary

Tubular bodies for use in frames for seats of vehicles such as aircraft are described. A tube can include a sidewall that has a variable thickness along the length of the tube. The variable thickness of the sidewalls can result in the tube having a variable inner diameter along the length of the tube. The tube may also include a variable outer diameter.