Pull-Out Rail Locking Mechanism for Defined Sequence Control

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Solution Overview

Problem

Existing pull-out guides for household appliances and furniture lack defined sequence control and functional reliability, particularly in locking and unlocking mechanisms, leading to imprecise latching forces and disruptive movement sequences.

Innovation Solution

A pull-out guide with a resiliently prestressed locking mechanism, featuring a blocking element that can be fixed to one of the rails, allowing for precise locking and unlocking with a compact design, and an unlocking member to prevent incorrect operation, ensuring high functional reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two latching means are provided in a full extension with at least three rails, then the running rail can be locked in one or more positions, but the latching forces can only be determined imprecisely and sequence control cannot be implemented

Engineering Contradiction:
Improvelatching reliabilityVSAvoidlatching force precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The locking mechanism is segmented into distinct functional components: a locking element with a blocking section for precise positioning, a resilient element for providing locking force, and an unlocking element for controlled release. This segmentation allows each component to perform its specific function with high precision, resolving the contradiction between reliable locking and precise force determination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The resilient element acts as an intermediary between the locking element and the rails, mediating the locking force transmission. This intermediary component enables precise control of latching forces while maintaining reliable locking, as the resilient element can be designed with specific mechanical properties to provide controlled force characteristics.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If locking in an intermediate position has to be canceled when the running rail is retracted or extended, then the locking mechanism can be simple, but the continuous movement is perceived as disruptive

Engineering Contradiction:
Improvemovement smoothnessVSAvoidlocking mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The locking mechanism incorporates dynamic characteristics through the resilient element that can flex and adapt during movement. The locking element can transition between locked and unlocked states dynamically, allowing smooth continuous movement while maintaining the ability to lock at intermediate positions without disruptive cancellations.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a locking element is used to block movement with high functional reliability, then defined sequence control can be provided, but the device complexity increases

Engineering Contradiction:
Improvefunctional reliabilityVSAvoidlocking mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple functions are merged into a compact locking mechanism structure. The locking element, resilient element, and unlocking element are integrated into a single coordinated system that provides defined sequence control and high functional reliability without excessive complexity. The components work together in a unified manner to achieve reliable operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The resilient element provides self-service by automatically providing the necessary locking force without external intervention. The locking mechanism can maintain its locked state and provide sequence control autonomously, reducing the need for additional control components and minimizing device complexity while maintaining high reliability.

Inventive Principle:
Principle #25Self-service

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 defined sequence control and high functional reliability during prolonged use, with precise locking and unlocking forces, and is suitable for various applications including high-temperature environments and clean rooms.

Implementation Method 1

a locking mechanism with a locking element which is resiliently prestressed into the locking position

Methodology Applied
Scientific EffectResilient prestress: Spring

Data Source

PatentEP2906078B1Pull-out guide
Publication Date: 2016.12.07 PAUL HETTICH GMBH & CO KG
  • EP2906078B1 patent drawingFigure 1~2
  • EP2906078B1 patent drawingFigure 3~4
  • EP2906078B1 patent drawingFigure 5~6

AI summary

A pull-out guide (1, 1', 1"), in particular for domestic appliances or furniture, comprises at least three rails (2, 3, 4) that are mounted so as to be movable relative to each other, one rail (2) being securable to a body and another rail (4) being connectible to a pull-out element. The pull-out device is provided with a locking mechanism (40, 50, 70, 70') for locking a first rail (2) relative to a second rail (3) in a predetermined position against movement, the locking mechanism (40, 50, 70, 70') comprising a locking element (42, 52, 74) that is resiliently biased in the locking position. The pull-out guide according to the invention can thus be provided with a defined sequence control.