Chair having a leaf spring with a working length that shortens to increase resistance to tilting of a backrest relative to a column

Solution Overview

Problem

Current furniture designs, particularly task chairs, face challenges in providing optimal adjustability to accommodate users of different weights and body types, leading to discomfort and potential health issues due to complex and time-consuming manual adjustment mechanisms.

Innovation Solution

A reconfigurable chair system featuring an adjusting assembly with a leaf spring and subassemblies that automatically adjust resistance to the backrest's angular orientation based on user weight, allowing for seamless transition from upright to reclined positions without excessive force, using a fulcrum point that moves to shorten the leaf spring's length and increase resistance as weight increases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual adjustment mechanisms are provided to accommodate users of different weights, then adaptability is improved, but device complexity increases

Engineering Contradiction:

Improveadaptability to different user weightsVSAvoidcomplexity of adjustment mechanisms

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The chair automatically adjusts the resistance force of the backrest based on the user's weight without requiring manual intervention. The system uses sensors to detect user weight and automatically modifies the spring constant or damping characteristics, allowing the chair to serve itself rather than requiring the user to manually adjust multiple mechanisms.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system changes physical parameters (such as spring constant, damping coefficient, or resistance force) based on detected user weight. By dynamically adjusting these parameters, the chair adapts to different users without adding complex mechanical adjustment mechanisms, thus improving adaptability while maintaining simplicity.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If manual adjustment mechanisms are provided to accommodate users of different weights, then adaptability is improved, but time consumption increases

Engineering Contradiction:

Improveadaptability to different user weightsVSAvoidtime for manual adjustments

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The chair automatically adjusts the resistance force of the backrest based on the user's weight without requiring manual intervention. The system uses sensors to detect user weight and automatically modifies the spring constant or damping characteristics, allowing the chair to serve itself rather than requiring the user to manually adjust multiple mechanisms.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system performs the adjustment action automatically as the user sits down, before the user needs to use the chair. By detecting user weight and pre-adjusting the resistance parameters, the system eliminates the need for subsequent manual adjustments during the user's sitting period.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If fixed resistance mechanisms are used in the backrest, then device complexity is reduced, but ease of operation deteriorates for users of different weights

Engineering Contradiction:

Improvesimplicity of adjustment mechanismsVSAvoidease of backrest adjustment

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The system changes physical parameters (such as spring constant, damping coefficient, or resistance force) based on detected user weight. By dynamically adjusting these parameters, the chair adapts to different users without adding complex mechanical adjustment mechanisms, thus improving adaptability while maintaining simplicity.

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 system ensures ergonomic support and comfort by automatically adjusting to user weight, reducing the need for manual adjustments and minimizing the effort required to change positions, thereby promoting healthy movement and reducing the risk of discomfort and injury.

Implementation Method 1

a leaf spring (434) having a length L and a working length l less than the length L

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

a fulcrum point (338) on the component (58) that moves relative to the leaf spring (434) along a movement path (440)

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentUS11950710B2Chair having a leaf spring with a working length that shortens to increase resistance to tilting of a backrest relative to a column

Publication Date: 2024.04.09 DEJULE AARON

AI summary

A chair, comprising, a backrest, a seat coupled with the backrest, a column coupled with the seat, a linkage statically attached to the backrest and rotatably attached below the seat, a leaf spring statically attached at one end and in direct contact with the linkage to provide a resistance to tilting of the backrest relative to the column, a first structure fixed to the column. A portion of the first structure has an arc shape that includes one or more teeth, and a second structure in contact with the first structure. The chair is configured such that, when a weight is applied to the seat, one or more teeth of the second structure move along the one or more teeth of the first structure to shorten a working length of the leaf spring and provide an increased resistance to tilting of the backrest relative to the column.