Seat Cushion with Deformable Side Support to Reduce Ischial Bone Load

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Solution Overview

Problem

Existing seat designs, even with evenly arranged springs, fail to provide adequate comfort and reduce fatigue during long periods of sitting due to intense load on ischial bones and hard support, leading to discomfort and poor blood circulation.

Innovation Solution

A seat configuration with deformable second support members that tilt inward when occupied, distributing pressure more evenly across the buttocks and femoral regions, and featuring a restraining mechanism to prevent the outer side from sinking, thus reducing pressure on ischial bones and enhancing comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If springs are arranged evenly in the cushion frame to support the seated occupant, then the seat structure is simple and manufacturing is easy, but the ischial bones receive intense load causing fatigue and poor blood circulation

Engineering Contradiction:
Improvespring arrangement simplicityVSAvoidischial bone load intensity
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The seat cushion is divided into multiple independent support regions: first support members (springs) arranged in the front-rear direction to support the ischial bones, and second support members (springs) arranged at left and right sides to support the femoral regions and side portions of buttocks. This segmentation distributes the load across different body regions rather than concentrating it on the ischial bones, resolving the contradiction between simple spring arrangement and reduced ischial bone load.

Inventive Principle:
Principle #1Segmentation

2Strength

If a pan frame is used to support the load of the seated occupant, then the seat provides strong support, but it creates a hard feel making the occupant uncomfortable

Engineering Contradiction:
Improveload support capabilityVSAvoidride comfort
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The second support members are configured to be deformable and are restrained such that their outer sides are less likely to sink down than their center sides. This creates a dynamic support system that adapts to the occupant's body shape while maintaining appropriate support strength. The deformable nature of the springs provides a softer, more comfortable feel compared to a rigid pan frame, while still delivering strong load support capability.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If plastic support members are provided to support the ischial bones from below, then the structure is simple, but the same problem of intense load on ischial bones occurs

Engineering Contradiction:
Improvesupport member structureVSAvoidischial bone load intensity
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

Instead of using a single plastic support member to support the ischial bones, the invention segments the support function into multiple spring elements distributed across different locations. The first support members support the ischial bones while the second support members support the femoral regions and side portions of buttocks. This segmentation distributes the load intensity across a broader area, reducing the harmful concentration of force on the ischial bones while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

4Object-affected harmful factors

If the second support members are made deformable to improve comfort, then ride comfort increases, but the support stability decreases

Engineering Contradiction:
Improveride comfortVSAvoidsupport stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The second support members are configured with specific restraint parameters that control their deformation characteristics. The restraining portion is designed so that the outer side of each second support member is less likely to sink down than the center side, creating a controlled deformation pattern. This parameter optimization allows the support members to be sufficiently deformable to conform to the occupant's body for comfort, while maintaining enough stability to provide reliable support.

Inventive Principle:
Principle #35Parameter changes

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 seat design reduces fatigue and discomfort by distributing pressure more evenly, preventing poor blood circulation and providing increased ride comfort regardless of the occupant's physique.

Implementation Method 1

second support members disposed at left and right sides of the first support member, the second support members being configured to be deformable

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3495200B1seat
Publication Date: 2022.09.07 TS TECH CO LTD
  • EP3495200B1 patent drawingFigure 1
  • EP3495200B1 patent drawingFigure 2
  • EP3495200B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is a seat which offers increased ride comfort and less fatigue felt even on long-time sitting. The seat includes a cushion frame (F1), a first support member (31) supported by the cushion frame (F1) and configured to support a seated occupant, second support members (32) disposed at left and right sides of the first support member (31) and configured to be deformable, and a restraining portion (34) by which each second support member is restrained in such a manner that its laterally outer side is less likely to sink down than its laterally center side. The seat is configured such that an upper-side support surface for supporting a seated occupant is so restrained by the restraining portion as to assume a first position when no occupant is seated, and to assume a second position when an occupant is seated, the support surface facing further inward in the second position than in the first position.