Composite Seat Pan Structure for Lightweight Crash Energy Absorption

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Solution Overview

Problem

Current seat pan structures are heavy, complex to assemble, and prone to degradation under continuous impacts, limiting their strength, comfort, and service life.

Innovation Solution

A seat pan formed from a lightweight thermoplastic composite material with integrated straps and covering strips, featuring slots and wave-shaped wrinkles for enhanced stiffness and elasticity, allowing for improved weight support and crash energy absorption while simplifying manufacturing and assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If sheet metals are used to form the seat pan, then strength is improved, but weight increases and dimension is limited

Engineering Contradiction:
Improveseat pan strengthVSAvoidseat pan weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent uses composite materials (such as glass fiber reinforced plastics or carbon fiber reinforced plastics) to manufacture the seat pan, combining the strength benefits of metal with the weight advantages of polymers. The composite material structure provides sufficient load-bearing capacity while significantly reducing overall weight compared to traditional metal sheet construction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters by transitioning from metal to polymer composite materials, altering the density and strength-to-weight ratio. This parameter change enables achieving the required strength levels with reduced weight, overcoming the fundamental limitation of metal-based seat pans.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If flexible seat pan structures with serpentine springs are used, then seating comfort is improved, but assembly complexity increases and reliability decreases

Engineering Contradiction:
Improveseating comfortVSAvoidassembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the flexible element directly into the seat pan structure during the molding process, creating an integrated one-piece component. The flexible portion is formed as an integral part of the seat pan rather than being a separate assembly, eliminating the need for additional fastening means and reducing assembly complexity while maintaining comfort benefits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces the mechanical spring system with a molded flexible portion that achieves similar elastic behavior through material properties and geometric design. This substitution eliminates complex mechanical assemblies in favor of a simplified monolithic structure with inherent flexibility.

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

3Ease of operation

If flexible seat pan structures with serpentine springs are used, then seating comfort is improved, but service life is shortened due to breakage under continuous impacts

Engineering Contradiction:
Improveseating comfortVSAvoidservice life
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The use of composite materials provides both flexibility and enhanced durability. The composite structure resists breakage under continuous impacts better than traditional spring systems while maintaining the elastic behavior needed for comfort. The material properties of composites offer superior fatigue resistance compared to metal springs.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

By integrating the flexible portion directly into the seat pan as a unified structure, the patent eliminates connection points and joints where breakage could occur. The monolithic construction removes weak points associated with separate spring assemblies and fastening mechanisms, significantly improving reliability under continuous loading conditions.

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 results in a lightweight, strong, and comfortable seat pan that effectively supports passenger weight and absorbs crash energy, with reduced manufacturing complexity and cost, while extending service life.

Implementation Method 1

the seat pan thus made can function well to withstand the weight of passenger and absorb crash energy

Methodology Applied
Scientific EffectEnergy absorption: Deformation

Implementation Method 2

covering strips are formed by overmolding onto the side edges of straps separated by the slot and extending along at least a portion of the circumference of the slot so as to reinforce the straps

Methodology Applied
Scientific EffectStiffness enhancement: Composite Materials

Implementation Method 3

at least one wave-shaped wrinkle comprising a groove and/or protrusion is provided on the straps

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3245099B1Seat pan and seat
Publication Date: 2019.04.03 BASF SE
  • EP3245099B1 patent drawingFigure 1
  • EP3245099B1 patent drawingFigure 2
  • EP3245099B1 patent drawingFigure 3~5

AI summary

The invention discloses a seat pan (20), being formed from a first thermoplastic composite material into a one-piece pan, the seat pan (20) having a weight loading portion (201), wherein at least one slot (2010) is provided in the area of the weight loading portion (201) of the seat pan (20), and covering strips (2012) are formed by overmolding on the side edges of straps (2011) separated by the slot (2010) and extending along at least a portion of the circumference of the slot (2010) so as to reinforce the straps (2011), the covering strips (2012) being made of a second thermoplastic composite material. Furthermore, the invention discloses a seat (1) comprising the above seat pan (20).