Backrest-Supported Armrest Design to Prevent Contact Damage

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Solution Overview

Problem

In chairs with armrests, the armrests can contact the backrest when moving up and down, causing damage or deterioration to the backrest.

Innovation Solution

The armrest is supported by a backrest support positioned behind and outside the backrest body, allowing it to move up and down without contacting the backrest, with a simpler structure and improved design by using a connecting part and shielding walls to secure the armrest support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the armrest is supported by a frame at the outer periphery of the backrest body, then the armrest can be positioned close to the backrest body, but the armrest may contact the backrest body when moving up and down, causing damage or deterioration

Engineering Contradiction:

Improvearmrest positioningVSAvoidbackrest body integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The support structure is divided into two separate components: the backrest body and the backrest support. The armrest is supported by the backrest support rather than the backrest body frame, separating the support function from the backrest body and eliminating contact between the moving armrest and the backrest body.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The backrest support acts as an intermediary structure between the backrest body and the armrest. It provides the necessary support for the armrest while maintaining a separation distance from the backrest body, preventing direct contact and potential damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the lifting and lowering mechanism is provided in the backrest support, then the armrest can move up and down, but the backrest support structure becomes complex

Engineering Contradiction:

Improvearmrest adjustabilityVSAvoidbackrest support structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The mechanism is segmented and placed in the armrest body support rather than the backrest support. This separates the complex mechanism from the simple backrest support structure, allowing the backrest support to remain structurally simple while still enabling armrest adjustability.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If the connection point between the connecting part and armrest body support is exposed, then the structure is simple, but the design level is reduced

Engineering Contradiction:

Improveconnection structureVSAvoidaesthetic appearance

Core Design Contradiction:

Ease of manufactureVSShape

Solution Approach 1:

The front shielding wall and rear shielding wall act as intermediaries that cover the connection point between the connecting part and armrest body support. These shielding walls hide the structural connection from view, improving aesthetic appearance while not interfering with the structural simplicity or manufacturing ease.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11439239B2Backrest and chair

Publication Date: 2022.09.13 OKAMURA CORP

AI summary

A backrest includes: a backrest body against which a seated person leans a back thereof, a backrest support positioned behind and supporting the backrest body; and an armrest body provided outside in a width direction of the backrest body and supported by the backrest support so as to move up and down at a position separated from the backrest body. A chair includes the above-described backrest.