Tensioned Flexible Backrest Contour to Eliminate Hard Contact Points

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Solution Overview

Problem

Conventional seating structures with flexible backrests often create undesirable hard contact points due to the use of peripheral frames or intermediate members, which can be uncomfortable and aesthetically unappealing.

Innovation Solution

A seating structure featuring a flexible backrest member made of elastomeric material, tensioned between upper and lower mounting portions, with a unique three-dimensional contour that eliminates the need for peripheral frames and intermediate members, providing a soft initial support that firms up as the user deflects the backrest rearwardly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a peripheral frame is used to hold the flexible member, then the flexible member can be supported in three-dimensional contour, but hard contact points are created which are uncomfortable and aesthetically unappealing

Engineering Contradiction:
Improvethree-dimensional contour supportVSAvoidhard contact points
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent removes the peripheral frame entirely from the design. Instead of using a frame to hold the flexible backrest member, the flexible member is tensioned between spaced-apart mounting portions, extracting the harmful frame element while preserving the necessary support function through the tensioning mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses the flexible backrest member itself as the primary structural element. By tensioning this flexible membrane between mounting portions, the system creates the three-dimensional contour without rigid frames, allowing the flexible film to provide both shape and support while eliminating hard contact points.

Inventive Principle:
Principle #30Flexible shells and thin films

2Shape

If intermediate members are used to push on the flexible member to form contours, then the flexible member can be shaped, but hard contact points are created which are uncomfortable

Engineering Contradiction:
Improvecontoured shapeVSAvoidhard contact points
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates intermediate members that push on the flexible backrest. Instead, the flexible member is tensioned directly between mounting portions, removing the source of hard contact points while maintaining the ability to create desired contours through the tensioning geometry.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates contours by utilizing the three-dimensional spatial arrangement of mounting portions rather than using intermediate pushing members. The flexible member assumes its contoured shape through tensioning across space between mounting points, achieving shaping without direct mechanical contact from intermediate elements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If the flexible member is tensioned between upper and lower mounting portions without peripheral frames, then hard contact points are eliminated, but the structural complexity increases

Engineering Contradiction:
Improveelimination of hard contact pointsVSAvoidmounting structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The mounting structure is segmented into multiple discrete mounting portions distributed in space (upper mounting portion, lower mounting portions, and intermediate mounting portion). This segmentation allows the flexible member to be tensioned at multiple points to create contours while eliminating the need for a continuous peripheral frame, reducing overall structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a two-dimensional planar mounting approach to a three-dimensional spatial arrangement of mounting portions. By positioning mounting portions at different heights and locations in space, the system creates complex contours and eliminates hard contact points without requiring a full peripheral frame structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 seating structure offers improved comfort and aesthetics by providing a flexible, tensioned backrest that maintains support without hard contact points, while allowing for adjustable lumbar support and enhanced load distribution.

Implementation Method 1

A flexible member has an upper portion connected to the upper mounting portion and a lower portion connected to the side mounting portions and the intermediate mounting portion. The flexible member includes side edges extending and tensioned between the upper mounting portion and the side mounting portions.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A tension vector directed away from the upper portion and taken along any point of either of the side edges has a forwardly extending component.

Methodology Applied
Scientific EffectTension: Tension

Data Source

PatentEP3081115B1Seating structure with a contoured flexible backrest
Publication Date: 2020.07.01 HERMAN MILLER INC
  • EP3081115B1 patent drawingFigure 1~3
  • EP3081115B1 patent drawingFigure 4~7
  • EP3081115B1 patent drawingFigure 8~10

AI summary

A seating structure includes a backrest member (160,84,85) having an upper edge (196,86), opposite side edges (90) and a lower edge (86,88). The backrest member (160,84,85) has a forwardly facing convex shape formed along a vertical centerline (106) thereof between the upper and lower edges (86,88). The lower edge (86,88) has a forwardly facing concave shape. The lower edge has outer portions positioned forwardly of an entirety of the upper edge (196,86).