Chair chassis and chair

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Solution Overview

Problem

Conventional chair backrest adjustment mechanisms are limited in allowing the backrest to adjust and fix at a desired angle, failing to move with the user's body movement, resulting in poor comfort.

Innovation Solution

A chair chassis with a backrest support system that includes a memory stopper, locking slider, elastic members, and a rack mechanism, allowing for reclination and pitching adjustments that lock and unlock to accommodate the user's position, enabling the backrest to adjust and maintain any desired angle for comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the backrest is adjusted to a fixed angle using a conventional adjustment mechanism, then the backrest can be positioned at a desired angle, but it fails to move with the user's body movement, resulting in poor comfort

Engineering Contradiction:
Improvebackrest adaptability to body movementVSAvoidbackrest adjustment operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent transforms the static fixed-angle adjustment mechanism into a dynamic system where the backrest support can automatically move and adapt to body movements. The elastic member provides continuous dynamic adjustment capability, allowing the backrest to follow body contours without requiring manual intervention, thus resolving the contradiction between adaptability and ease of operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The backrest support system performs self-adjustment through the elastic member that automatically responds to body movements. The mechanism serves itself by detecting body position changes and autonomously adjusting the backrest angle, eliminating the need for user operation while maintaining high adaptability to body contours

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If the backrest support is made elastically restorable to follow body movement, then comfort is improved, but the structure becomes more complex compared to conventional fixed mechanisms

Engineering Contradiction:
Improvebackrest support flexibilityVSAvoidbackrest adjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The backrest adjustment system is segmented into distinct functional components: the backrest support, the elastic member, and the locking mechanism. This segmentation allows each component to perform its specific function independently, making the overall complex system manageable and maintainable while achieving the desired flexibility and adaptability

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If a locking mechanism is added to maintain backrest position, then position stability is improved, but the mechanism complexity increases

Engineering Contradiction:
Improvebackrest position stabilityVSAvoidlocking mechanism complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The locking slider acts as an intermediary component that mediates between the backrest support and the base. It provides the locking function by engaging with the rack on the backrest support, stabilizing the position without requiring a complex dedicated locking mechanism. The slider's simple sliding motion along the guide groove keeps the locking mechanism straightforward while achieving position stability

Inventive Principle:
Principle #24Intermediary (Mediator)

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 allows for unlimited adjustment of reclination angles, ensuring the backrest moves with the user's body, providing improved comfort and support by locking and unlocking the backrest's position relative to the user's body.

Implementation Method 1

a first elastic member, connected between the locking slider and the base, and configured to supply a restoration elastic force for sliding towards the memory stopper to the locking slider

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

an elastic slider, slidably disposed in the accommodation chamber of the base, wherein one end of the elastic slider is provided with a second rack, wherein the second rack is meshable with the first rack, and configured to limit and lock the locking slider

Methodology Applied
Scientific EffectMechanical meshing: Gear

Implementation Method 3

a third elastic member, connected between the active slider and the base, and configured to supply an elastic force for sliding towards the elastic slider to the active slider

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 4

the active slider is provided with a first inclined surface, and the elastic slider is provided with a second inclined surface, wherein in the case that the active slider slides towards the elastic slider under action of the third elastic member, the first inclined surface and the second inclined surface slide relative to each other such that the elastic slider slides towards the locking slider and the second rack is meshed with the first rack

Methodology Applied
Scientific EffectMechanical advantage through inclined surfaces: Inclined Plane

Data Source

PatentEP4094628B1Chair chassis and chair
Publication Date: 2023.06.21 COMFORT OFFICE FURNITURE CO LTD GUANGDONG
  • EP4094628B1 patent drawingFigure 1
  • EP4094628B1 patent drawingFigure 2
  • EP4094628B1 patent drawingFigure 3

AI summary

A chair chassis (100) includes: a base (110), provided with an accommodation chamber (111); a backrest support (120); a memory stopper (130), disposed on the backrest support (120), wherein the memory stopper (130) is provided with a first arc surface (131) facing the base (110); a locking slider (140), slidably disposed in the accommodation chamber (111) of the base (110), wherein the locking slider (140) is provided with a second arc surface (141) disposed opposite to the first arc surface (131), and a side of the locking slider (140) is provided with a first rack (143); a first elastic member (150); and an elastic slider (160), slidably disposed in the accommodation chamber (111) of the base (110), wherein one end of the elastic slider (160) is provided with a second rack (161), wherein the second rack (161) is meshable with the first rack (143).