Plastic Film Seat Back Suspension for Lightweight Assembly

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current metal suspension sheets for vehicle seatbacks are heavy, complex to assemble, and contribute to noise transmission and design constraints, while also increasing manufacturing costs and weight.

Innovation Solution

A lightweight suspension sheet composed of overmolded plastic film strips and polymer side uprights that adapt to the seat frame's profile, simplifying assembly and reducing the number of non-woven parts, with the strips and uprights designed to enhance comfort and guide airbag deployment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal wires are used for suspension system, then mechanical strength is ensured, but weight increases and assembly complexity increases

Engineering Contradiction:

Improvemechanical strengthVSAvoidweight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent replaces the traditional metal wire mechanical suspension system with a plastic film-based system. The plastic film is stretched and tensioned between side supports to create the suspension effect, substituting metal components with polymer materials that are lighter in weight while maintaining the necessary mechanical function through elastic deformation and tension.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses a plastic film as the core suspension element instead of rigid metal wires. The film is stretched and tensioned to create a flexible suspension network that provides both weight reduction and mechanical support. The thin film structure allows for lightweight construction while maintaining suspension functionality through its elastic properties.

Inventive Principle:

Principle #30Flexible shells and thin films

2Stability of the object's composition

If metal suspension system is used, then structural stability is maintained, but noise transmission increases

Engineering Contradiction:

Improvestructural stabilityVSAvoidnoise transmission

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent substitutes metal components with plastic film and polymer side supports. The plastic film, when stretched and tensioned, provides structural stability while inherently dampening noise vibrations. The polymer materials have better acoustic damping properties compared to metal, reducing noise transmission from the suspension system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If multiple separate components are used for suspension system, then adjustability is improved, but assembly difficulty increases

Engineering Contradiction:

ImproveadjustabilityVSAvoidassembly difficulty

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent integrates the suspension function directly into the seat backrest structure by incorporating plastic film tensioning elements and side supports as part of the overall backrest assembly. This merging of functions simplifies assembly compared to separate metal wire suspension systems that require individual component installation, while still providing adjustability through the tensioning mechanism.

Inventive Principle:

Principle #5Merging (Combining)

4Ease of operation

If traditional suspension system is used, then comfort is provided, but manufacturing cost increases

Engineering Contradiction:

ImprovecomfortVSAvoidmanufacturing cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The patent employs plastic film and polymer materials that are generally less expensive than metal components. The plastic film can be mass-produced through stretching and cutting processes, and the polymer side supports can be injection-molded, resulting in lower material and manufacturing costs compared to precision metal wire fabrication and assembly.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material parameters from metal to plastic/polymer, which fundamentally alters the manufacturing process and cost structure. The plastic film allows for simpler fabrication methods such as stretching, cutting, and thermal bonding, replacing complex metal forming and assembly operations, thereby reducing manufacturing costs while maintaining comfort functionality.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4015302B1Lightweight suspension sheet with simplified assembly

Publication Date: 2023.11.29 RENAULT SA

Figure 1~2
Figure 3~4
Figure 5~6

AI summary

The invention relates to a suspension system (3, 103) for a vehicle seat backrest (1, 100). According to the invention, the suspension system comprises at least two strips (120, 123, 124, 125) of a plastic film overmolded into two lateral supports (121, 122), said two lateral supports (121, 122) each having a profile intended to fit the profile of a lateral flange (7, 8) of a frame (102) of said backrest (1, 100).