Vehicle Curtain Strap with Low-Elongation Aramid Stuffer Strands

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Solution Overview

Problem

Existing vehicle side curtains fail to effectively restrain loads during transportation, leading to potential load shifts that can cause instability and safety risks due to lateral forces and motion-related movements.

Innovation Solution

The vehicle side curtain incorporates straps with stuffer strands made of high-strength aramid fibers, such as Technora, which resist elongation and maintain tensile strength at elevated temperatures, ensuring effective load restraint by minimizing strap elongation and maintaining structural integrity under load shifts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional straps are used for load restraint, then the curtain can be manufactured with standard materials, but the straps elongate under tensile forces leading to ineffective load restraint

Engineering Contradiction:
Improveload restraint effectivenessVSAvoidstrap elongation resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the material parameter of the strap by incorporating stuffer strands with elongation at break of less than 7.5%, which is significantly lower than conventional strap materials. This parameter change ensures that the strap maintains its length and restraint effectiveness under tensile forces during load transport.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The strap is constructed as a composite material system combining stuffer strands (providing elongation resistance) with casing material (providing structural integrity). This composite structure allows the strap to simultaneously achieve low elongation and high strength, resolving the contradiction between reliability and strength.

Inventive Principle:
Principle #40Composite materials

2Reliability

If high-strength stuffer strands are used in the straps, then load restraint effectiveness is improved, but the manufacturing complexity and material cost increase

Engineering Contradiction:
Improveload restraint effectivenessVSAvoidstrap manufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The strap is segmented into distinct functional components: stuffer strands (for elongation resistance) and casing (for structural support). This segmentation allows each component to be optimized independently and manufactured using standard processes, reducing overall manufacturing complexity despite the specialized material requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stuffer strands serve multiple functions simultaneously: they provide elongation resistance, maintain strap tension, and contribute to the overall structural integrity. This multi-functionality reduces the need for additional specialized components, simplifying the manufacturing process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Strength

If the stuffer strands have very low elongation at break, then the strap resists elongation effectively under load, but the strap becomes more brittle and susceptible to sudden failure

Engineering Contradiction:
Improveelongation resistanceVSAvoidfailure resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The casing surrounding the stuffer strands acts as a cushioning element that distributes stress and prevents sudden catastrophic failure. The casing provides a buffer zone that allows for gradual stress distribution, preventing the brittle stuffer strands from failing suddenly under excessive load.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The composite structure combines brittle stuffer strands (for elongation resistance) with more ductile casing material (for failure resistance). This composite approach allows the system to benefit from the low elongation of the stuffer strands while the casing provides toughness and prevents sudden failure, resolving the contradiction between strength and reliability.

Inventive Principle:
Principle #40Composite materials

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 curtain effectively resists load shifts and maintains stability by utilizing high-strength, temperature-resistant stuffer strands within the straps, enhancing safety and preventing load protrusion beyond the load bed.

Implementation Method 1

the stuffer strands resist elongation of the respective strap in response to tensile forces applied in the elongate direction of the strap

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2429845B1Strap for a vehicle side curtain or load restraint
Publication Date: 2014.12.24 POLYWELD
  • EP2429845B1 patent drawingFigure 1~2
  • EP2429845B1 patent drawingFigure 3~4
  • EP2429845B1 patent drawingFigure 5~7

AI summary

There is disclosed a strap that includes a casing, and a plurality of stuffer strands that extend lengthwise through the casing. The stuffer strands are located between two layers of the casing and are arranged in at least two sets. The stuffer strands resist elongation of the strap in response to tensile forces applied in the elongate direction of the strap, and have a maximum elongation at break of less than 7.5%.