Angle Adjuster with Sliding Winding Member for Overload Protection

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Solution Overview

Problem

Existing angle adjusters for furniture items, such as sofa headrests and armrests, are prone to destruction or damage when an overload is applied, leading to costly repairs and potential disposal of the entire furniture piece.

Innovation Solution

The implementation of winding and tightening members that rotate before components undergo plastic deformation, preventing damage and allowing the angle adjuster to be reusable after an overload is removed, with embodiments including clamping of attachment portions or annular flanges on rotating shafts to enhance holding strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional joint devices are used to allow angle adjustment in furniture items, then the inclination angle can be adjusted to user preference, but the components are prone to destruction or damage when extreme overload is applied

Engineering Contradiction:
Improveangle adjustmentVSAvoidcomponent durability under overload
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A resilient member is pre-installed in the angle adjuster to act as a cushion against extreme overload. When excessive force is applied during angle adjustment, the resilient member deforms elastically to absorb the overload energy, preventing transmission of destructive forces to other components like the cam plate and claw piece. This beforehand cushioning protects the system while allowing normal angle adjustment operations.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If conventional joint devices are used without overload protection, then the structure remains simple, but the furniture item requires disassembly for repair or complete disposal when components are damaged

Engineering Contradiction:
Improvestructure simplicityVSAvoidrepairability and cost
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The resilient member is designed as a sacrificial component that can withstand extreme overload through elastic deformation. While it absorbs the overload energy, it may become permanently deformed or damaged, but this protects more expensive components. The resilient member itself is relatively inexpensive and can be replaced without disassembling the entire furniture item, making repair simple and cost-effective compared to replacing the entire angle adjuster assembly.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If the resilient member is designed to absorb extreme overload through elastic deformation, then component destruction is prevented, but the resilient member itself may become permanently deformed or damaged

Engineering Contradiction:
Improveprotection of componentsVSAvoidresilient member integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The resilient member is designed with specific material properties and geometric parameters that allow it to undergo controlled elastic deformation within a safe stress range. By carefully selecting the material's Young's modulus, yield strength, and the member's cross-sectional area and length, the design ensures that under extreme overload, the stress remains below the yield point, allowing full elastic recovery without permanent deformation. This parameter optimization balances protection capability with component integrity.

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 effectively prevents destruction or damage to components, making the angle adjuster reusable and eliminating the need for repairs or disposal of the furniture item due to overload-induced damage.

Implementation Method 1

when an extreme overload is applied to the rocking body, the resilient member deforms elastically to absorb the overload

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3925488B1Angle adjuster and furniture item using the same
Publication Date: 2023.11.15 KOYO GIKEN KK
  • EP3925488B1 patent drawingFigure 1~2
  • EP3925488B1 patent drawingFigure 3
  • EP3925488B1 patent drawingFigure 4

AI summary

Provided is an angle adjuster (10) that can avoid destruction or damage of components when an overload is applied and that is reusable after the overload is removed, and a furniture item using the angle adjuster (10). The angle adjuster (10) includes a support (20), a rotating shaft (40) supported at one end of the support (20) so as not to rotate, a winding and tightening member (50) in pressure contact with an outer peripheral surface of the rotating shaft (40), and a rocking body (30) having an attachment portion (32) on one end, the attachment portion (32) being connected to the rotating shaft (40) via the winding and tightening member (50), in which when an overload is applied to the rocking body (30), an increase in a frictional force of the winding and tightening member (50) to the outer peripheral surface of the rotating shaft (40) is restricted, and the overload causes the winding and tightening member (50) to slide on the outer peripheral surface of the rotating shaft (40) and rotate.