Two-Part Quarter-Turn Locking Device for Tool-Free Assembly

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Solution Overview

Problem

Conventional quarter-turn locking devices for door leaves are costly and time-consuming to assemble due to the need for tools and complex mounting processes, leading to high assembly costs when repeated.

Innovation Solution

A two-piece locking device structure with a manipulation head and locking cam, where the first part pivots relative to the leaf wall, and the second part is assembled to sandwich the wall, allowing for easy assembly without tools and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional quarter-turn locking device with at least three elements (main body, locking cam, mounting nut) is used, then the locking function is reliable, but the assembly process requires tools and consumes significant time, leading to high assembly costs

Engineering Contradiction:
ImproveAssembly easeVSAvoidAssembly time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The locking device is divided into two main parts: a first part comprising the manipulation head and locking cam, and a second part that sandwiches the leaf wall. This segmentation allows for simpler, tool-free assembly while maintaining the reliable locking function through the coordinated interaction of these parts

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mounting function is integrated directly into the two-part structure itself, eliminating the need for a separate mounting nut. The second part serves both as a mounting component and as part of the locking mechanism, reducing the total number of components and simplifying assembly

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a conventional locking device with multiple components is used, then the locking mechanism is robust, but the device complexity increases and manufacturing costs rise

Engineering Contradiction:
ImproveLocking reliabilityVSAvoidNumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

By segmenting the device into two functional parts rather than three or more separate components, the patent reduces device complexity while maintaining reliability through the specific design of each part's function and their coordinated interaction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The two parts are designed to perform multiple functions: the first part provides manipulation and locking cam functions, while the second part serves as both a mounting component and structural element. This multi-functionality reduces the overall number of components needed

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If a conventional locking device requiring tool-based assembly is used, then precise mounting is achievable, but assembly costs increase significantly when repeated many times

Engineering Contradiction:
ImproveMounting precisionVSAvoidAssembly cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The two-part structure is designed to self-align and self-mount without requiring external tools. The parts work together to achieve precise mounting through their inherent geometric compatibility and assembly features, eliminating the need for tool-based precision mounting procedures

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2236713B1Quarter turn locking device formed of two elements
Publication Date: 2012.05.09 PINET IND
  • EP2236713B1 patent drawingFigure 1~4
  • EP2236713B1 patent drawingFigure 5~7
  • EP2236713B1 patent drawingFigure 8~10

AI summary

The device (100) has a piece (110) constituted of an operating head (112), a body (114) and a locking cam (116). Another piece (130) is assembled at the former piece, such that the head and the latter piece hook a wall (150) of a doorleaf, and the former piece is freely pivoted with respect to the wall of the doorleaf, when the device is assembled. The former piece has a stop unit for limiting a rotation course of the cam with respect to the wall to quarter turn.