Chair

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Solution Overview

Problem

Conventional chairs lack a mechanism to automatically lock and unlock the movement of the back and seat independently without requiring manual operation, leading to instability and discomfort during seating and movement.

Innovation Solution

A chair with a weight-receiving part on the seat that changes height position, mechanically transmitting this change to a control mechanism to control the operation of movable parts, allowing or suppressing movements like tilting, swinging, or rolling without manual intervention, using an engagement system with elastic members to ensure secure locking and unlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a movable part is introduced in a chair to allow the back and seat to be used in appropriate positions, then the adaptability and comfort of the chair is improved, but the movable part is not locked after a seated person leaves the seat to cause instability and anxiety at the time of the next seating

Engineering Contradiction:

Improveadaptability of back and seat positionsVSAvoidstability of chair when seat is empty

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The control mechanism automatically detects the seating state through the weight-receiving part and autonomously controls the locking and unlocking of the movable part, eliminating the need for manual operation. The system serves itself by using the presence or absence of weight to trigger the appropriate locking state

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The weight-receiving part provides feedback about the seating state to the control mechanism, which then adjusts the locking state of the movable part accordingly. This feedback loop ensures the chair is locked when empty and unlocked when occupied

Inventive Principle:

Principle #23Feedback

2Reliability

If the movable part is mechanically restricted to prevent movement after the seated person leaves, then the stability is improved, but it is troublesome for a seated person to operate an operating part to restrict the movable part every time the seated person leaves the seat

Engineering Contradiction:

Improvestability of chair when seat is emptyVSAvoidease of operating locking mechanism

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The control mechanism automatically performs the locking operation based on weight detection, eliminating the need for manual intervention. The system handles the locking task itself without requiring user operation

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The locking action is performed automatically as soon as the weight is removed, preparing the chair in the locked state before the next seating occurs, thus preventing any period of instability

Inventive Principle:

Principle #10Preliminary action

3Extent of automation

If the configuration uses a back frame rotatably coupled to a pedestal to control seat movement, then automatic restriction is achieved, but the structure becomes large and complicated and is unsuitable for chairs where the back is not directly attached to the seat

Engineering Contradiction:

Improveautomatic restriction of movable partVSAvoidcomplexity of control mechanism structure

Core Design Contradiction:

Extent of automationVSDevice complexity

Solution Approach 1:

The weight detection function is extracted from the back frame structure and placed in the seat itself through the weight-receiving part. This separates the detection function from the complex back frame mechanism, simplifying the overall structure

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The weight-receiving part serves multiple functions: it detects seating state, transmits weight information to the control mechanism, and enables automatic locking control. This multi-functionality reduces the need for separate components

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables easy and comfortable operation of the chair by automatically changing the state of movable parts based on the seating position, providing stability and ease of use without the need for manual operation, ensuring secure locking when the seat is empty and unlocking when occupied.

Implementation Method 1

an elastic member configured to store elastic energy in accordance with a deformation of the elastic member and release the stored elastic energy to drive an operation of an engaging part

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS11202509B2Chair

Publication Date: 2021.12.21 KOKUYO CO LTD

AI summary

[Problem] Provided is a chair capable of changing an operation of a movable part between allowed and suppressed states, without causing an up-down movement of a seat or without requiring a complicated structure relying on a back.[Solution] For that purpose, a weight-receiving part 50, the height position of which changes due to a person sitting on a seat surface, is provided on a seat 5, the change of the height position is mechanically transmitted to a control mechanism 8X configured to control an operation of a front-rear swing part 3 being the movable part, and the control mechanism 8X changes an operation of the front-rear swing part-3 being the movable part between allowed and suppressed states.