Chair and chair structure

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Solution Overview

Problem

Conventional chairs face issues with a deteriorated fine appearance due to overlapping members, loose elastomer seating boards, and discomfort from rigid attachments, as well as inadequate consideration for user contact with the seating surface.

Innovation Solution

A chair design featuring a seating board made of elastomer with a rigid first fixing portion and a support body secured using a specified securing member, where the first fixing portion is a frame member along the edge of the seating surface, reducing deformation and user discomfort, and a leg tip is housed in a recess to minimize protrusion and enhance stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the seating board is made of elastomer to improve comfort, then the seating comfort is improved, but the seating board becomes loose and screws get loosened and disengaged

Engineering Contradiction:
Improveseating comfortVSAvoidattachment reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The seating board is constructed as a composite structure combining elastomer material (for comfort) with a rigid frame member (for structural stability). The rigid frame member has higher rigidity than the elastomer seating portion, providing stable screw engagement while the elastomer maintains seating comfort. This composite approach resolves the contradiction between comfort and attachment reliability.

Inventive Principle:
Principle #40Composite materials

2Strength

If multiple members are arranged to overlap in the outer peripheral to provide structural support, then the structural strength is improved, but the fine appearance deteriorates due to thicker outer peripheral

Engineering Contradiction:
Improvestructural strengthVSAvoidfine appearance
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The leg tip is housed within a recess formed on the columnar portion of the leg, creating a nested structure. This allows the leg tip to be integrated into the leg structure rather than protruding externally, maintaining structural support functionality while improving the fine appearance by minimizing visible thickness in the outer peripheral region.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If the leg tip widely protrudes downward to protect the floor and reduce noise, then the protective function is improved, but the fine appearance deteriorates

Engineering Contradiction:
Improvefloor protection and noise reductionVSAvoidfine appearance
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The leg tip is nested within a recess on the columnar portion, allowing it to extend downward for floor protection and noise reduction while being partially concealed. This nested arrangement maintains the protective function against floor scratches and reduces dragging noise, while simultaneously improving fine appearance by reducing the visible protrusion of the leg tip.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 design ensures secure attachment of the seating board, reduces deformation and user discomfort, improves sitting comfort, and maintains a refined appearance by minimizing the thickness of visible components and reducing the leg tip's protrusion.

Implementation Method 1

a front edge portion having at least one of a plate shape or a planar shape, the front edge portion being configured such that a front end of the front edge portion is elastically deformable in a top-bottom direction

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

The seating board includes a seating portion forming a seating surface and made of at least elastomer

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3516993B1Chair and chair structure
Publication Date: 2021.08.18 AICHI CO LTD
  • EP3516993B1 patent drawingFigure 1A~1G
  • EP3516993B1 patent drawingFigure 2A~2B
  • EP3516993B1 patent drawingFigure 3

AI summary

Provided is a chair including a support member that is at least a seat body and a backrest to support an occupant. The support member includes a composite portion at least a part of an outer periphery of the support member. The composite portion includes a first outer periphery that is a part of the first member and a second outer periphery that is a part of the second member. The first outer periphery and the second outer periphery are arranged to overlap each other in a thickness direction of the support member. In the composite portion, at least a part of the first outer periphery is formed into a thin portion thinner in the thickness direction than a part located on an outside of at least the part of the first outer periphery in the first member.