Pliable-Wall Air Duct with Internal Expansion to Prevent Sagging

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Solution Overview

Problem

Metal air ducts in warehouse and manufacturing environments face issues such as condensation leading to mold and bacteria growth, uncomfortable drafts, and unsightly sagging when deflated, along with noise from sudden inflation.

Innovation Solution

The implementation of a pliable-wall air duct system with an internal framework that maintains the duct in a taut, expanded shape using a central shaft and radial spokes, preventing buckling and ensuring consistent airflow and appearance, regardless of pressure changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a fabric duct is used instead of metal duct, then condensation and mold problems are reduced, but the duct sags when deflated and creates noise during inflation

Engineering Contradiction:
Improvecondensation and mold growthVSAvoidduct sagging and appearance
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The patent uses a fabric duct with a flexible porous wall that allows the duct to be lightweight and resistant to condensation, while incorporating an internal framework to maintain shape when deflated

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The internal framework is divided into multiple radial support members spaced along the duct length, with circumferential clamps securing them to the fabric wall, creating a segmented support structure that prevents sagging

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a fabric duct is used instead of metal duct, then air distribution is improved, but the duct produces loud popping sounds during inflation

Engineering Contradiction:
Improveairflow distributionVSAvoidinflation noise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The flexible fabric wall allows gradual inflation without the sudden snapping sound associated with rigid structures, while the internal framework provides gradual support as air pressure builds

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The internal framework is pre-installed within the fabric duct before inflation, providing gradual structural support that cushions against sudden fabric tensioning and prevents popping sounds during the inflation process

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

3Shape

If an internal framework is added to maintain duct shape, then duct appearance and airflow consistency are improved, but device complexity increases

Engineering Contradiction:
Improveduct tautness and consistencyVSAvoidframework structure
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The fabric duct itself serves as the primary structural element, requiring only a relatively simple internal framework rather than a complex rigid structure, thereby maintaining shape while minimizing added complexity

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The framework is segmented into discrete radial support members spaced along the duct, each independently clamped to the fabric wall, simplifying installation and reducing overall structural complexity while effectively preventing sagging

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2641028B1Pliable-wall air duct with internal expanding structures and method of retrofitting an air duct
Publication Date: 2017.04.26 RITE HITE HLDG CORP
  • EP2641028B1 patent drawingFigure 1~4
  • EP2641028B1 patent drawingFigure 5
  • EP2641028B1 patent drawingFigure 6

AI summary

Pliable-wall air ducts with internal expanding structures are disclosed. An example air duct system includes a shaft to be disposed within an air duct, to extend in a longitudinal direction, and to be in longitudinal compression. The air duct system also includes a plurality of ribs to be coupled to the shaft and to engage an inner surface of the air duct and a spring to be disposed within the air duct, the spring to be coupled to the shaft. The spring under stress being a contributing factor in both the shaft being in longitudinal compression and the air duct being in longitudinal tension. A method of retrofitting an existing air duct system with internal expanding structure is also disclosed.