Pull-Out Guide Preliminary Coupling to Prevent Drawer Detachment

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Solution Overview

Problem

Existing pull-out guides for drawers lack protection against assembly errors, which can lead to the drawer being pulled off the runners during movement, posing a risk of injury and damage.

Innovation Solution

A additional coupling device, comprising a catch hook or spring-loaded lever, is integrated between the runners and the drawer to create a trigger lock that secures the drawer before the primary coupling devices are fully engaged, preventing unintentional detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If only two coupling devices (front and rear) are used to fix the drawer on the running rail, then the device complexity is low, but the reliability is insufficient because the drawer can be pulled off if proper coupling is not achieved

Engineering Contradiction:
Improvedrawer coupling reliabilityVSAvoidnumber of coupling devices
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention introduces a further coupling device that becomes effective before the drawer is fully pushed in, providing preliminary security against the drawer being pulled off. This preliminary action ensures that even if the front and rear coupling devices are not properly engaged, the drawer remains secured to the running rail throughout the entire insertion process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The further coupling device acts as a safety mechanism that compensates for potential assembly errors or improper installation. By providing an additional coupling point that engages early in the insertion process, it cushions against the harmful effect of the drawer being pulled off, preventing injury and damage.

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

2Reliability

If the drawer is not pushed in far enough during assembly, then the ease of operation is improved (easier to install), but the reliability deteriorates because the coupling devices may not be properly engaged

Engineering Contradiction:
Improvecoupling engagement reliabilityVSAvoiddrawer installation difficulty
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The further coupling device provides immediate feedback through its mechanical engagement that the drawer has been properly inserted. As the drawer is pushed in, this coupling device engages first and provides a clear indication that the drawer is securely attached, giving users confidence that the installation is correct without requiring complex verification procedures.

Inventive Principle:
Principle #23Feedback

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

This solution enhances safety by ensuring the drawer is securely attached before full engagement, preventing accidents and damage by maintaining the drawer on the runners even if assembly is incomplete or incorrect.

Implementation Method 1

the catch hook being designed to be resilient towards the running rail or provided with a spring-loaded lever towards the running rail

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3019046B1Pull-out guide for a drawer
Publication Date: 2017.09.06 PAUL HETTICH GMBH & CO KG
  • EP3019046B1 patent drawingFigure 1~2
  • EP3019046B1 patent drawingFigure 3~5
  • EP3019046B1 patent drawingFigure 6~7

AI summary

The invention concerns a pull-out guide (4) for a drawer (2), with a runner (6) that can be coupled to a drawer (2), and with a front and a rear coupling device which can be used to secure the drawer (2) on the runner (6), a further coupling device, which secures the drawer (2) at least against being pulled down off the runner (6), being in engagement with the drawer before at least one of the two other coupling devices.