Pull-Out Guide Coupling Mechanism for Carriage Error Correction

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Solution Overview

Problem

Carriage errors in pull-out guide systems for drawers, caused by slippage between rollers and rails, lead to incorrect positioning, which can result in drawers being left open or failing to close properly due to reduced kinetic energy from damping devices.

Innovation Solution

A coupling mechanism using a loosely guided rolling or sliding body that moves at twice the speed of the carriage, correcting errors by coupling and decoupling with the drawer's movement, and a spring device to return the rolling body to its initial position during closure, allowing for precise alignment and free movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If damping devices are added to reduce closing momentum, then the drawer closing force is reduced, but the kinetic energy becomes insufficient to correct carriage errors

Engineering Contradiction:
Improvedrawer closing forceVSAvoidcarriage error correction
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The coupling mechanism is activated before the drawer reaches the closed position. During the opening phase, the rolling body couples the carriage to the drawer, allowing error correction to occur in advance. This preliminary coupling ensures that carriage errors are corrected before the damping devices reduce the kinetic energy, resolving the contradiction between reduced closing force and error correction reliability.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the rolling body is loosely guided to move at twice the carriage speed, then carriage errors are corrected effectively, but the coupling mechanism complexity increases

Engineering Contradiction:
Improvecarriage positioning accuracyVSAvoidcoupling mechanism structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A rolling or sliding body serves as an intermediary element between the carriage and the drawer. This intermediary couples the two components during opening movement, allowing the faster-moving drawer to correct carriage positioning errors. The rolling body simplifies the coupling mechanism by using a single intermediate component rather than complex linkages, achieving high positioning accuracy with minimal structural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the rolling body is coupled to the drawer throughout the entire movement, then positioning accuracy is maintained, but the drawer movement freedom is restricted

Engineering Contradiction:
Improvecarriage positioning accuracyVSAvoiddrawer movement freedom
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The coupling between the rolling body and the drawer occurs periodically rather than continuously. The rolling body engages with the drawer during the opening phase when error correction is needed, then disengages to allow free movement. This periodic coupling maintains positioning accuracy when necessary while preserving drawer movement freedom during normal operation, resolving the contradiction between precision and ease of operation.

Inventive Principle:
Principle #19Periodic action

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

Effectively corrects carriage errors during opening and ensures proper closure without the need for complex structural components, maintaining drawer functionality and reducing wear on components.

Implementation Method 1

the rolling or sliding body, preferably under the force of gravity, is mounted so that it can move vertically essentially perpendicular to the direction of extension of the rails

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

the rolling or sliding body can be acted upon within the guide by a spring device, by means of which the rolling or sliding body can be moved back into an initial position

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2144531B1Pull-out guide for drawers
Publication Date: 2017.06.21 JULIUS BLUM GMBH
  • EP2144531B1 patent drawingFigure 1
  • EP2144531B1 patent drawingFigure 2
  • EP2144531B1 patent drawingFigure 3

AI summary

The invention relates to a pull-out guide (3) for drawers (6) comprising a first and at least one second rail (5, 7), at least one carriage (9) with load-transmitting roller bodies (10) being arranged between said two rails (5, 7). The carriage (9) can be coupled to the second rail (5), particularly when deviating from the differential course between the two rails (5, 7), characterized in that a rolling or sliding body (12) is mounted in a freely movable manner on or in the carriage (9), through which the carriage (9) can be coupled to a coupling part (8) on the second rail (5), and that a recess (14) is provided in the first rail (7) into which the rolling or sliding body (12) can be moved during opening of the drawer (6), wherein the coupling part (8) can de decoupled from the rolling or sliding body (12) and passes along the carriage (9).