Reclining Chair Mechanism With Hip-Aligned Pivot and Seat Lift

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Solution Overview

Problem

Existing seating apparatuses fail to provide optimal comfort by having an incorrectly positioned recline pivot point, leading to discomfort and the 'shirt tail pull' problem, and they often require multiple sizes to fit various users, which is inefficient for manufacturers and users.

Innovation Solution

A seating apparatus with a curved support bar and ramps that allow for coordinated reclining motion, where the seat and backrest move in tandem, with the recline pivot point aligned with the user's hip joints, and a spring component that facilitates easy movement between upright and reclined positions, while maintaining foot contact with the floor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the recline pivot point is positioned at the center of the body (through hip joints), then the reclining motion aligns with natural body action and avoids shirt tail pull, but the mechanical structure becomes more complex to achieve this precise pivot positioning

Engineering Contradiction:
Improvereclining motion comfortVSAvoidpivot positioning mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The curved support bar serves multiple functions: it provides structural support, defines the recline pivot point through its geometry, and guides the coordinated movement of seat and backrest. This multi-functionality eliminates the need for separate pivot positioning mechanisms, resolving the contradiction between comfort and complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The curved support bar uses a circular arc geometry where the radius and positioning of the curve naturally establish the pivot point at the user's hip joint level. This geometric approach simplifies the mechanism while achieving the desired pivot location for natural reclining motion.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If the seat and backrest are connected for correlative movement, then the recline action parallels natural body action and relieves internal pressures, but the mechanical connection requires additional components like ramps and motion-facilitating components

Engineering Contradiction:
Improvebody pressure reliefVSAvoidconnection mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The seat support and backrest support are merged into a single curved support bar structure. This integration allows the seat and backrest to move in coordination through their shared connection to the curved bar, achieving natural body alignment while reducing the number of separate mechanical components needed.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The curved support bar acts as an intermediary element that mediates the movement between the seat and backrest. It translates backrest rotation into coordinated seat movement through its geometric constraints, facilitating natural reclining without requiring complex direct connection mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If a single chair design is used for all users, then manufacturing and stocking is simplified, but the chair cannot comfortably fit users of various sizes

Engineering Contradiction:
Improveproduction efficiencyVSAvoiduser size accommodation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The chair incorporates dynamic adjustment capabilities through the curved support bar mechanism, allowing the seat position and recline characteristics to adapt to different user sizes and preferences. This enables a single chair design to comfortably accommodate various users without requiring multiple size variants.

Inventive Principle:
Principle #15Dynamics

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 solution provides improved comfort by aligning the recline pivot with the user's body, relieving internal pressures, and avoiding the 'shirt tail pull' issue, while allowing for a natural reclining motion that maintains foot contact and simplifies chair design and aesthetics.

Implementation Method 1

a spring component positioned between, and rigidly connected to, the seat support and the back rest support

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP1945063B1Seating apparatus with reclining movement
Publication Date: 2015.12.09 HUMANSCALE CORP
  • EP1945063B1 patent drawingFigure 1
  • EP1945063B1 patent drawingFigure 2
  • EP1945063B1 patent drawingFigure 3

AI summary

The invention provides a seating apparatus having a reclining movement with a corresponding seat lift movement. The apparatus further provides a seating support surface having increased comfort comprising a shaped diaphragm with a series of calculated openings provided throughout.