Over-Extension Drawer Slide With Gap-Filling Tongue Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Differential pull-out guides with over-extension suffer from impaired smoothness due to the catwalk extending out of and threading into the gap between the differential roller and the support roller, causing noticeable movement and potential synchronism issues during extension and retraction.

Innovation Solution

A tongue is mounted on the center rail that can be displaced between passive and active end positions, with a displacement device that moves the tongue into the gap between the differential roller and the support roller when the catwalk moves out, reducing the gap width and improving running properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the differential roller is mounted with play relative to the center rail to ensure reliable engagement, then the reliability of roller engagement is improved, but the smoothness of operation deteriorates due to the catwalk extending out of and threading into the gap between the differential roller and support roller

Engineering Contradiction:
Improveroller engagement reliabilityVSAvoidoperation smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A tongue is introduced as an intermediary element between the catwalk and the gap between the differential roller and support roller. The tongue is pushed into this gap when the catwalk moves out, acting as a mediator that prevents the catwalk from directly extending into the gap, thereby eliminating the harmful effect while preserving the necessary play in the differential roller for reliable engagement

Inventive Principle:
Principle #24Intermediary (Mediator)

2Length of moving object

If the catwalk moves out of the gap between the differential roller and support roller to achieve over-extension, then the pull-out distance is increased, but the smoothness of operation deteriorates due to noticeable movement and potential synchronism issues

Engineering Contradiction:
Improvepull-out distanceVSAvoidoperation smoothness
Core Design Contradiction:
Length of moving objectVSEase of operation

Solution Approach 1:

The tongue is prepared in advance by pushing it into the gap between the differential roller and support roller before the catwalk fully moves out. This preliminary action ensures that when the catwalk does move out to achieve over-extension, the tongue is already in position to minimize the transition effects, preventing noticeable movement and maintaining smooth operation

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2428136B1Drawer slide
Publication Date: 2013.10.23 FULTERER GES
  • EP2428136B1 patent drawingFigure 1~2
  • EP2428136B1 patent drawingFigure 3~4
  • EP2428136B1 patent drawingFigure 5~6

AI summary

A rail structure (1) fastens to a furniture structure relative to a carcass rail (1) displaceably guided by a central rail (2) on one above other. A differential roller (17) is equipped with a match portion in vertical direction. An extension rail (3) is moved from a gap formed between differential roller and support roller (16). A tongue portion is displaceably mounted on central rail. Displacement devices (31,32) are moved from a passive end position in which tongue portion is outside, and to an active end position in which tongue portion is inserted at gap.