Split Seat Chair Mechanism for Stable Lateral Pivoting

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Solution Overview

Problem

Existing chair designs with lateral pivoting movements require constant user cooperation to prevent tipping and restrict freedom of movement due to rigid seat structures, compromising safety and comfort.

Innovation Solution

A chair design featuring independently movable right and left seat sides, pivotally mounted about a knee-axis parallel to the user's knees, with ball joints and spring systems allowing for independent pivoting and adjustment to accommodate different user weights, ensuring stability and comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the seat is designed as a rigid structure with centralized swivel joint, then the mechanical stability is improved, but the freedom of movement and adaptation to body movements is restricted

Engineering Contradiction:
Improvemechanical stabilityVSAvoidfreedom of movement
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The seat is divided into two independently movable halves (left and right sides), each capable of pivoting about the knee axis. This segmentation allows each side to move independently, providing freedom of movement while maintaining overall structural stability through the coordinated operation of both halves.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The seat design incorporates dynamic elements including resilient means (springs) that allow the seat halves to move independently and return to neutral position. The pivoting mechanism about the knee axis enables continuous adjustment, transforming the rigid structure into a dynamic system that adapts to user movements.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the seat allows lateral pivoting movement, then the adaptation to natural movements is improved, but the safety and stability in upright position deteriorates

Engineering Contradiction:
Improveadaptation to natural movementsVSAvoidsafety and stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

Resilient means (springs) are incorporated to provide counteracting forces that return the seat halves to their neutral upright position after lateral pivoting. This counterweight mechanism ensures that the seat maintains stability in the upright position while still allowing natural lateral movements during use.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The design allows for adjustment of the resilient means to modify the strength and characteristics of the restoring force. This parameter adjustment capability enables optimization of both the lateral movement freedom and the stability in upright position, allowing users to customize the balance between adaptability and safety.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the entire seat tilts as a rigid element, then the structural simplicity is maintained, but the independent movement of seat sides is restricted

Engineering Contradiction:
Improvestructural simplicityVSAvoidindependent movement of seat sides
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The seat is divided into two independent halves that can pivot separately about the knee axis. This segmentation enables each side to move independently, providing enhanced adaptability to natural body movements while maintaining relatively simple individual structures for each half.

Inventive Principle:
Principle #1Segmentation

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 allows for natural three-dimensional movement while maintaining safety in the upright position, enabling comfortable sitting with independent seat and backrest mobility, and adjustable spring systems for personalized fit.

Implementation Method 1

a first spring system being provided between the base support and the seat and a second spring system being provided between the seat and the backrest

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP1946676B1Chair
Publication Date: 2011.03.09 WILKHAHN WILKENING HAHNE GMBH & CO
  • EP1946676B1 patent drawingFigure 1a~1c
  • EP1946676B1 patent drawingFigure 1d~1e
  • EP1946676B1 patent drawingFigure 1f~1g

AI summary

The chair has a seat (1) and a seat mechanism (2), where the seat mechanism permits a sideways pivoting movement of the seat. The seat and the seat mechanism are formed such that one side of the seat is movable independently of the other side of the seat, during the sideways pivoting movement of the seat. The seat mechanism is formed so that the seat is mounted to be pivotable about a rotation axis lying parallel to a knee axis of a user. The seat has a seat surface (10) and a backrest (11), where the backrest and the seat surface are movable relative to one another.