Flexible member with adjustable stiffness for bedding and/or seating furniture

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing flexible elements with adjustable stiffness for seating and sleeping furniture are complex and bulky, failing to provide a simple and compact solution for adapting to different user preferences and anatomies.

Innovation Solution

A flexible element with adjustable stiffness featuring radially deforming springs and a rotary part with elastically flexible fingers, allowing for gradual adjustment of resistance through rotation, enabling the creation of a support surface with adjustable firmness by varying the overhang of the springs, and potentially integrating multiple elements for simultaneous adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If complex mechanisms are used to adjust stiffness of flexible elements, then stiffness adjustment capability is improved, but device complexity and footprint increase

Engineering Contradiction:
Improvestiffness adjustment capabilityVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs a dynamic adjustment mechanism where a rotating element changes the position of spring anchors along flexible fingers. This allows the stiffness of the flexible element to be continuously adjusted by rotating the element, which modifies the cantilever length of the spring anchors. The dynamic reconfiguration of the spring-finger arrangement enables stiffness adaptation without complex mechanical structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the geometric parameter of the spring-finger system by rotating the adjustment element, which alters the effective cantilever length of the spring anchors. This parameter change (rotation angle) directly controls the stiffness characteristic of the flexible element, providing a simple yet effective way to adjust mechanical properties without adding complexity.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If existing adjustment mechanisms are implemented, then stiffness variability is improved, but structural footprint and bulk increase

Engineering Contradiction:
Improvestiffness variabilityVSAvoidstructural footprint
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges the adjustment mechanism with the existing spring-finger structure. The rotating element is integrated into the assembly, and the spring anchors are positioned along the flexible fingers rather than being fixed. This merging allows the adjustment function to be achieved within the existing structural envelope, minimizing additional footprint while providing variability in stiffness.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention introduces rotational movement in a third dimension (around the central axis) to achieve stiffness adjustment. Instead of linear extension or complex multi-axis mechanisms, the solution uses rotation to reposition spring anchors, effectively using angular displacement to control mechanical stiffness. This dimensional approach compactly packs the adjustment mechanism within a small radial space.

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 solution provides a simple, compact, and adjustable flexible element that can be integrated into furniture, allowing for customizable firmness and comfort by adjusting the resistance of the springs, enhancing user experience through adaptable support surfaces.

Implementation Method 1

one or more adjustable springs, each configured to deform radially about a central axis under the effect of an axial stress along the central axis

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

one or more elastically flexible fingers, each extending from a first end fixed to the hub of the rotating part, along an arc of a circle around the central axis, to a second end... each cooperating, in a radial direction about the central axis, with one or more of the adjustable springs

Methodology Applied
Scientific EffectElastic bending: Elasticity

Data Source

PatentEP3669705B1Flexible member with adjustable stiffness for bedding and/or seating furniture
Publication Date: 2021.09.22 TOURNADRE STANDARD GUM
  • EP3669705B1 patent drawingFigure 1A~1B
  • EP3669705B1 patent drawingFigure 2A~2B
  • EP3669705B1 patent drawingFigure 3A~3B

AI summary

The invention relates to a flexible element (10) with adjustable stiffness for a sleeping and/or seating unit (200, 300). This element (10) comprises one or more adjustable helical springs (15, 16) and a rotating part (20). The rotating part (20) has a hub (21) capable of rotating about the central axis (Z) and one or more elastically flexible fingers (23). Each finger (23) extends from a first end (23a) fixed to the hub (21) of the rotating part (20), along an arc (A) around the central axis (Z), to a second end (23b), and cooperates with a corresponding end (15a, 16a) of one or more of the adjustable helical springs (15, 16).