A flexible backrest for a folding chair, and folding chair comprising this backrest
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Folding chairs with increased backrest height for lumbar support are hindered by the need for a single curvature in the backrest panel to maintain deformability between use and storage positions, preventing the inclusion of anatomically shaped lumbar support areas.
Innovation Solution
A flexible backrest panel with a concave shape in a horizontal plane and a convex shape in a vertical plane, featuring vertical through-slits to subdivide the surface into deformable slats, allowing for both anatomical lumbar support and flexibility between curved use and extended storage configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the backrest height is increased to provide lumbar support, then user comfort is improved, but the backrest cannot be deformed to extended position for storage
Solution Approach 1:
The backrest panel is divided into multiple independent slats separated by vertical through-slits. Each slat can move independently relative to others, allowing the panel to deform from curved (arched) position to extended position while maintaining lumbar support structure. The segmentation enables the backrest to achieve both comfort and storage requirements simultaneously.
2Ease of operation
If a convex zone is added for lumbar support, then anatomical comfort is improved, but the backrest panel becomes non-deformable
Solution Approach 1:
The lumbar support zone is formed by specific slats that can be shaped with convex curvature, while the entire panel remains deformable through the through-slits. Each slat acts as an independent element that can maintain its convex shape for lumbar support while the overall panel can still transition between curved and extended positions.
Solution Approach 2:
Different zones of the backrest panel have different curvatures - the lumbar support area has convex curvature for anatomical comfort, while other areas have concave curvature. The through-slits allow these different curvature zones to coexist without preventing panel deformability, as each local zone maintains its quality while the whole remains flexible.
3Ease of operation
If the backrest assumes curved configuration for comfort, then user support is improved, but storage volume increases
Solution Approach 1:
The backrest panel transitions dynamically between two configurations: curved (arched) position during use for user support, and extended position for compact storage. The through-slits enable this dynamic transformation by allowing the slats to move relative to each other, reducing storage volume while maintaining comfort during use.
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 enhanced comfort through anatomical lumbar support while maintaining the ability to deform between use and storage positions, ensuring efficient storage and comfortable seating.
Implementation Method 1
a flexible backrest (26) having a support surface (30) with a double curvature, i.e. with a first curvature in a horizontal plane and a second curvature in a vertical plane, perpendicular to the first curvature
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A flexible backrest for a folding chair, comprising a flexible backrest panel (26) which can assume a curved configuration of use and an extended storage configuration, wherein the backrest panel (26) has a support surface (30) having a concave shape in a cross-section in a horizontal plane, and a convex shape in a cross-section in a vertical plane, and wherein the backrest panel (26) has a plurality of vertical through-slits (32) forming a plurality of vertical slats (34).