Retraction device for a drawer pullout

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Solution Overview

Problem

Existing drawer pull-out mechanisms are complex and costly due to their intricate construction, which is not economically viable without ejection functionality, and they require significant space for retraction and blocking devices.

Innovation Solution

A simplified retraction device with a pivoting element and locking slide mechanism, where the pivoting element is blocked by a locking slide in a blocking position, utilizing a single or multiple helical springs for mechanical stability and low production costs, and incorporating a damping element for smooth operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex retraction device with multiple components is used, then reliable automatic retraction and locking functionality is achieved, but device complexity and production costs increase

Engineering Contradiction:
Improvereliable automatic retractionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the retraction device and locking device into a single integrated mechanism. The carriage serves dual functions: it performs automatic retraction of the inner rail while also engaging with the locking strip to prevent simultaneous drawer operation. This merging eliminates the need for separate retraction and locking mechanisms, reducing overall device complexity while maintaining reliability of both functions

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The carriage is designed as a multi-functional component that simultaneously performs retraction, locking, and ejection functions. It interacts with both the inner rail for retraction and the locking strip for safety locking, making a single component perform multiple critical functions that would traditionally require separate devices

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

2Reliability

If traditional retraction and locking devices are installed, then safety and functionality are ensured, but space requirements increase

Engineering Contradiction:
Improvesafety functionalityVSAvoidspace requirements
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

By integrating the locking device into the retraction device structure, the patent reduces the spatial footprint required for safety functionality. The locking strip and carriage share the same operational space, eliminating the need for additional dedicated locking mechanism space

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If ejection functionality is included, then complete drawer control is achieved, but production costs increase

Engineering Contradiction:
Improveejection functionalityVSAvoidproduction costs
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The carriage is designed to perform multiple functions including retraction, locking, and ejection. By making the same component multi-functional rather than adding separate ejection mechanisms, the patent achieves complete drawer control while avoiding the increased production costs that would result from additional specialized components

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

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 provides a mechanically robust and cost-effective drawer pull-out mechanism with reduced complexity, preventing simultaneous drawer extraction and minimizing noise and risk of injury, while ensuring reliable automatic retraction and ejection functionality.

Implementation Method 1

spring means which are arranged between the carriage and the guide receptacle and which apply a spring force to the carriage in the direction of retraction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

incorporating a damping element for smooth operation

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3518707B1Retraction device for a drawer pullout
Publication Date: 2021.06.23 USM U SCHAERER SOEHNE
  • EP3518707B1 patent drawingFigure 1~2
  • EP3518707B1 patent drawingFigure 3~4
  • EP3518707B1 patent drawingFigure 5~6

AI summary

A retraction device (10) for a drawer mechanism comprises a spring-loaded carriage (40) that can be moved in the push-in/pull-out direction for temporary coupling to an inner rail (4) of the drawer mechanism. The carriage (40) can be blocked in a retraction position by means of a locking slide (21, 22) that can be moved transverse to the push-in/pull-out direction in a guide. For coupling to the inner rail (4), the carriage (40) has at least one pivot element (45, 46), which can be pivoted about an axis oriented perpendicular to the push-in/pull-out direction and perpendicular to the direction of movement of the locking slide (21, 22). The pivot element (45, 46) and guide are arranged in such a manner that, in a locking position, the locking slide (21, 22) blocks a pivoting movement of the pivot element (45, 46). This results in simple construction and thus low costs and high mechanical stability.