Pivoting Sled Back Support for Parallel Lumbar Alignment in Chairs

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Solution Overview

Problem

Conventional seating structures often lead to user discomfort and poor posture due to inadequate support, particularly in the lumbar region, resulting in issues like fatigue, muscle strain, and long-term back pain, as they fail to accommodate the natural curvature of the spine effectively.

Innovation Solution

A back support system for chairs featuring a frame with a central opening, a suspended membrane, and a sled mechanism that pivots to adjust between positions, providing customizable support by moving between a low sacral and high lumbar position, ensuring the central portion remains parallel to the membrane, thus aligning with the user's back.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible backrest is used to accommodate user movements, then adaptability is improved, but lumbar support effectiveness deteriorates

Engineering Contradiction:
Improveaccommodation of user movementsVSAvoidlumbar support effectiveness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The backrest is divided into multiple independent support members including a lumbar support member and a sacral support member. Each segment can independently adjust and provide targeted support to specific regions of the user's back, maintaining support effectiveness while allowing flexibility for user movements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support members are configured to be adjustable in position and orientation. The lumbar support member can be positioned at different heights and angles, and the sacral support member can be adjusted independently, allowing the system to adapt to different user positions and movements while maintaining proper lumbar support.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If the backrest structure is simplified, then ease of manufacture is improved, but postural support capability deteriorates

Engineering Contradiction:
Improvebackrest structure simplicityVSAvoidpostural support capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The backrest is segmented into multiple support members (lumbar support member, sacral support member) that can be manufactured as separate, standardized components. This segmentation allows each component to be manufactured independently using simple processes, while the combination of segments provides comprehensive postural support capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support members are designed with universal adjustment capabilities that allow them to serve multiple functions. The same lumbar support member can be positioned to support different users with different postures, eliminating the need for complex custom-made components for each user.

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

3Stability of the object's composition

If fixed backrest positioning is used, then structural stability is improved, but user comfort deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoiduser comfort
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The backrest support members are designed to be dynamically adjustable by the user. The lumbar support member can be moved to different positions and angles, and the sacral support member can be adjusted independently, allowing users to customize the support according to their comfort needs while maintaining structural stability through controlled adjustment mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustment mechanisms are designed to be user-operable without requiring external assistance or complex controls. Users can independently adjust the position and angle of the support members to achieve optimal comfort, making the system self-adapting to individual user needs.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3257403B1Adjustable back support for a seating surface
Publication Date: 2020.08.05 HERMAN MILLER INC
  • EP3257403B1 patent drawingFigure 1
  • EP3257403B1 patent drawingFigure 2~3
  • EP3257403B1 patent drawingFigure 4

AI summary

A back support for a chair includes a cover (44) configured to be coupled to opposing sides of a chair frame. A strap (42) is connected to the cover (44). A sled (40) having a central portion is coupled to the strap (42), the sled (40) is configured to pivot with respect to the chair frame and provide support to a user's back. The cover (44) is configured to moveably connect to the chair frame between a low position and a high position. The sled (40) is configured to pivot as the cover moves between the low position and the high position so that the central portion of the sled (40) is substantially parallel to at least a portion of a membrane connected to the frame between the low position and the high position.