Adjustable Chair Lumbar Assembly for Smooth Secure Positioning

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Solution Overview

Problem

Current lumbar support devices in chair backrests lack optimal comfort, ease of manufacturing, smooth adjustability, durability, and security in adjusted positions, while also being simple to assemble and operate effectively.

Innovation Solution

A vertically adjustable lumbar assembly with a lumbar frame, transition shell, lumbar device support, and lumbar-energy wires, featuring wave ridges and alignment stops for smooth adjustment and secure positioning, integrated with a back support and cushion assembly using a "ZIP-LOCK" connection for easy assembly and disassembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lumbar device is designed to be adjustable and comfortable, then comfort and lumbar support effectiveness are improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
ImproveadjustabilityVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The lumbar device is divided into multiple segments including a lumbar frame, transition shell, lumbar device support, and adjustable lumbar support elements. This segmentation allows each component to perform a specific function while maintaining overall adjustability and comfort without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lumbar device incorporates dynamic adjustment mechanisms that allow the lumbar support to be adjusted to different positions and angles. The device includes movable components that can be repositioned while maintaining structural integrity, providing adaptability without requiring an overly complex system

Inventive Principle:
Principle #15Dynamics

2Reliability

If a lumbar device is made robust and durable, then reliability is improved, but manufacturing complexity and assembly difficulty increase

Engineering Contradiction:
ImprovedurabilityVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple structural components are merged into integrated assemblies such as the lumbar frame that combines support structures, adjustment mechanisms, and mounting features into a single robust unit. This merging provides durability while simplifying manufacturing and assembly processes

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lumbar device incorporates universal components that serve multiple functions, such as the lumbar frame that provides both structural support and adjustment capabilities, and the transition shell that protects internal components while facilitating assembly. This multi-functionality reduces the number of separate parts needed, simplifying manufacturing while maintaining robustness

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

3Ease of operation

If a lumbar device allows smooth adjustment between positions, then ease of operation is improved, but security in selected position may be compromised

Engineering Contradiction:
Improvesmooth adjustmentVSAvoidposition security
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The device incorporates intermediary elements such as the transition shell and lumbar device support that act as mediators between the adjustable lumbar support and the fixed lumbar frame. These intermediaries enable smooth adjustment motion while providing stability and security to the selected position through their structural design

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If a lumbar device is designed for easy assembly and disassembly, then ease of manufacture is improved, but structural robustness may be reduced

Engineering Contradiction:
Improveassembly simplicityVSAvoidstructural robustness
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The lumbar device is segmented into modular components including the lumbar frame, transition shell, lumbar device support, and adjustable support elements that can be easily assembled and disassembled. Each segment is designed with standardized connection interfaces that maintain structural robustness while facilitating simple assembly and disassembly operations

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 solution provides optimal comfort and secure positioning with smooth, fluid adjustment of lumbar support, ensuring durability and ease of assembly, while accommodating manufacturing tolerances for robust and efficient operation.

Implementation Method 1

lumbar-energy wires

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

wave ridges and alignment stops for smooth adjustment and secure positioning

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2462838B1Back support witch adjustable lumbar device
Publication Date: 2014.01.15 STEELCASE INC
  • EP2462838B1 patent drawingFigure 1~2
  • EP2462838B1 patent drawingFigure 3~4
  • EP2462838B1 patent drawingFigure 5

AI summary

A chair (10) includes a lower back frame (14), a back construction (18), including a back support (24) attached to the lower back frame (14), a cushion assembly (26) attached to the back support (24), and a vertically adjustable lumbar assembly (28). The lumbar frame includes a transition shell (102) and a vertically sliding lumbar device (108) having a plurality of horizontal flexible wires (109). A lower edge (114) of the transition shell (102) is positioned on top of an uppermost horizontal flexible wire of the lumbar device (108). The lumbar device (108) is operably slidably mounted between the outer shell (24) and cushion assembly (26) and the transition shell upper edge slides (112) between the outer shell (24) and the upholstery cushion assembly (26). Another chair includes a Y-shaped lower back frame (14) having two uprights (32) and a cross-piece (34) attached to the back support. An overlap flange (44) and channel-shaped flange (32) mate to form an overlap joint, including a box beam (98) for added structural support.