Rotational Locking Device for Play-Free Seating Furniture Adjustment

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Solution Overview

Problem

Existing locking devices for office chairs often result in rattling noises and play due to linear guides, which are difficult to manufacture and install, and require significant space.

Innovation Solution

A locking device with a first and second locking component that engage through rotational movement, eliminating the need for linear guides and allowing for silent locking without play, using a pivotally mounted locking body and an actuating element with a transmission element to manage the locking and unlocking positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If linear guides are used for the locking body, then the locking device can guide the locking body, but it causes rattling noises and play

Engineering Contradiction:
Improvelocking stabilityVSAvoidrattling noises
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the linear guide mechanism with a rotational movement system. The locking body rotates about an axis instead of moving linearly within guides, eliminating the guide structures that cause rattling and play. This substitution of mechanical movement type resolves the noise issue while maintaining locking reliability.

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

2Reliability

If linear guides with parallel guide surfaces are used, then the locking body can be guided, but it requires significant installation space

Engineering Contradiction:
Improveguiding accuracyVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent transitions from linear guidance in one dimension to rotational movement in a different dimensional approach. The locking body rotates about an axis rather than moving linearly, which changes the spatial requirements and reduces the installation space needed for guiding structures.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If linear guides are used to minimize play, then locking without play is achieved, but it increases device complexity and manufacturing difficulty

Engineering Contradiction:
Improvelocking precisionVSAvoidguide structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex linear guide structures with a simpler rotational mechanism. The locking body rotates about an axis defined by two parallel pins, eliminating the need for complex linear guides while achieving precise locking without play. This reduces both manufacturing complexity and device complexity.

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

4Reliability

If linear guides are used for the locking body, then the locking function can be implemented, but it increases the number of parts and assembly difficulty

Engineering Contradiction:
Improvelocking functionVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces multiple linear guide components with a simplified rotational system using two parallel pins and a rotating locking body. This substitution reduces the number of parts and simplifies assembly, as the rotational movement is inherently constrained by the two pins without requiring additional guide structures.

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

Data Source

PatentEP3741257A1Locking device
Publication Date: 2020.11.25 BOCK 1
  • EP3741257A1 patent drawingFigure 1~3
  • EP3741257A1 patent drawingFigure 4~5
  • EP3741257A1 patent drawingFigure 6~7

AI summary

The invention relates to a locking device for locking a first component of a piece of seating furniture relative to a second component of the seating furniture. To provide a piece of seating furniture with a locking device that enables backlash-free locking, a locking device (15) is proposed, comprising a first locking component (16) attached or attachable to the first component (5) and a second locking component (18) that can engage with the first locking component (16) for the purpose of locking and disengage for the purpose of unlocking, for which purpose the first locking component (16) and/or the second locking component (18) can be moved from a locked position to an unlocked position and back again by performing a rotary movement.