Chair Angle Adjuster With Friction Wrap for Stepless Recline

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Solution Overview

Problem

Existing angle adjusters for reclining chairs face challenges in reducing size and ease of assembly, with limited stepless adjustment capabilities and noise issues during operation.

Innovation Solution

The design incorporates a winding-and-tightening member with spring elasticity that acts on the rotation shaft portion, eliminating the need for a fixed boss portion and allowing for stepless adjustment of the development angle, while preventing unexpected rotations through controlled frictional forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed boss portion and rotation boss portion structure is used to prevent rotation, then the angle adjuster can prevent unexpected rotations, but the thickness dimension increases and assembly becomes difficult

Engineering Contradiction:
Improveprevention of unexpected rotationVSAvoidthickness dimension
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The invention extracts the rotation prevention function from the complex fixed boss portion and rotation boss portion structure, implementing it instead through frictional force between the winding-and-tightening member and rotation shaft portion. This eliminates the need for protruding boss portions, thereby reducing the thickness dimension while maintaining rotation prevention capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces frictional force as an intermediary mechanism between the winding-and-tightening member and rotation shaft portion. This frictional interaction serves as the mediator to prevent unexpected rotation without requiring mechanical interlocking structures like boss portions, thus achieving a more compact design.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a fixed boss portion and rotation boss portion structure is used to prevent rotation, then the angle adjuster can prevent unexpected rotations, but the assembling operation becomes difficult

Engineering Contradiction:
Improveprevention of unexpected rotationVSAvoidassembling operation
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention removes the complex assembly requirements of fixing the winding-and-tightening member to the rotation boss portion. Instead, the friction-based rotation prevention mechanism allows for simpler assembly where the winding-and-tightening member simply needs to engage with the rotation shaft portion through friction, eliminating difficult fixing operations.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If gear teeth and ratchet claw engagement is used for angle adjustment, then the structure can provide stepwise adjustment, but the development angle cannot be adjusted steplessly and click noise is produced

Engineering Contradiction:
Improveangle adjustment capabilityVSAvoidclick noise
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The invention replaces the mechanical gear teeth and ratchet claw engagement system with a friction-based winding-and-tightening mechanism. This substitution eliminates the discrete stepwise engagement that produces click noise, allowing for smooth, stepless angle adjustment while maintaining operational control through frictional forces.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the adjustment mechanism from discrete gear tooth engagement to continuous friction-based control. By varying the frictional force between the winding-and-tightening member and rotation shaft portion, the development angle can be adjusted continuously without the stepwise increments and associated click noise of gear mechanisms.

Inventive Principle:
Principle #35Parameter changes

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 enables a compact size reduction of the angle adjuster, simplifies assembly, and allows for quiet, stepless adjustment of the reclining chair's angle without the 'click' noise, ensuring reliable operation and user convenience.

Implementation Method 1

a winding-and-tightening member (5) having spring elasticity, one end portion (5a) and the other end portion (5b) of which are pivotally fixed to the first arm (1) in a rotatable manner

Methodology Applied
Scientific EffectSpring elasticity: Elasticity

Implementation Method 2

the frictional force acts on the winding-and-tightening member (5) in the winding-and-tightening direction, thereby making it possible to prevent the rotation of the second arm (10) in the reverse rotation direction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2845515B1Angle adjuster
Publication Date: 2016.05.18 HIKARI CO LTD
  • EP2845515B1 patent drawingFigure 1
  • EP2845515B1 patent drawingFigure 2~3
  • EP2845515B1 patent drawingFigure 4~5

AI summary

An angle adjuster (71) is equipped with a first arm (1) provided with a winding-and-tightening member (5) and a second arm (10) provided with a rotation shaft portion (13). As seen in the axial direction of the rotation shaft portion (13), one end portion (5a) and the other end portion (5b) of the winding-and-tightening member (5) are provided at the first arm (1) in a manner in which they are separated from each other. The first arm (1) and the second arm (10) are connected so that the second arm (10) is rotatable centering the rotation shaft portion (13) in a state in which the winding-and-tightening portion (6) of the winding-and-tightening member (5) is wound on the outer peripheral surface (13a) of the rotation shaft portion (13). It is configured so that a rotation of the second arm (10) by a frictional force (SM) and (GM) generated by a rotational movement of the second arm (10) in a forward rotation direction (S) or a reverse rotation direction (G) is allowed or prevented.