Chair assembly

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional chair assemblies fail to provide stable and comfortable seating due to limitations in adjustable reclining angles and unstable center of gravity, leading to inadequate support and risk of toppling.

Innovation Solution

A chair assembly design featuring a base, a supporting frame with guiding grooves, a seat with pivotable connections to the backrest and operating rods, allowing independent adjustment of reclining angles and inclining positions to maintain stability and comfort, with a footrest mechanism for enhanced support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the seat is designed with a smaller upward inclining angle to support user weight, then sitting comfort is improved, but the ability to provide lying comfort is reduced

Engineering Contradiction:
Improvesitting comfortVSAvoidlying comfort capability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic adjustability by allowing the seat to change its inclining angle from a smaller angle during sitting to a larger angle during lying. The seat includes a movable connection between the seat plate and base, enabling the seat to pivot and adjust its inclination angle according to different usage scenarios, thus providing both sitting and lying comfort.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If the backrest and seat are fixed at a fixed angular relation, then structural simplicity is maintained, but the ability to independently control backrest angular position is lost

Engineering Contradiction:
Improvestructural simplicityVSAvoidindependent backrest angle control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent segments the adjustment mechanisms by providing independent control for the backrest angle and seat inclination angle. The backrest is connected to the seat through a pivotal connection with an adjusting mechanism, while the seat has an independent movable connection with the base. This segmentation allows each component to be adjusted independently, enhancing adaptability while maintaining reasonable structural complexity.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the seat pivots rearwards while the backrest reclines, then lying comfort is improved, but the center of gravity becomes unstable causing the chair to topple

Engineering Contradiction:
Improvelying comfortVSAvoidcenter of gravity stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent addresses the stability issue by designing the movable connection between the seat and base with proper geometric constraints and guiding mechanisms. The seat plate can pivot to increase inclination angle, but the connection structure ensures that the center of gravity remains within a stable range through guided motion paths and appropriate pivot point positioning, preventing the chair from toppling while still providing lying comfort.

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

4Ease of operation

If the upward inclining angle of the seat is increased significantly to impart user weight to the backrest, then lying comfort is improved, but the chair becomes unstable due to gravity shifting behind the base

Engineering Contradiction:
Improvelying comfortVSAvoidchair stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic angle adjustment with controlled ranges. The seat can increase its inclination angle to provide lying comfort, but the movable connection structure defines specific angular limits that prevent the center of gravity from shifting too far behind the base. This dynamic control with geometric constraints ensures both comfort and stability are maintained within safe operating parameters.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3788912B1Chair assembly
Publication Date: 2021.12.15 LIN CHANG CHEN
  • EP3788912B1 patent drawingFigure 1
  • EP3788912B1 patent drawingFigure 2
  • EP3788912B1 patent drawingFigure 3

AI summary

A chair assembly includes a supporting frame (2) disposed above a base (1) and including a first guiding groove (24). A seat (4) is pivotably connected to a backrest (3). Lower and front guiding wheels (451) are mounted to rear and front ends of the seat (4), respectively. At least one operating board (51) includes rear and front ends respectively having second and third guiding grooves (54,55). The lower guiding wheel (442) is movably received in the first and second guiding grooves (24,54). The front guiding wheel (451) is movably received in the third guiding groove (55). A first operating rod (7) is pivotably connected between the supporting frame (2) and the seat (4). When the operating rod (7) retracts, the lower guiding wheel (442) is located in rear ends of the first and second guiding grooves (24,54), and the front guiding wheel (451) is located in a rear end of the third guiding groove (55). The seat (4) moves downwards and rearwards, and the front end of the seat (4) inclines upwards.