Pull-Out Fitting with Freewheel Coupling for Extended Pantry Access

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Solution Overview

Problem

Existing pull-out fittings for narrow pantries struggle to move object carriers with shelves out of the cabinet effectively due to limited leverage and travel distance, restricting accessibility of objects stored on the shelves.

Innovation Solution

A pull-out fitting with a bidirectional coupling mechanism using a tension-pressure arm articulated at both ends, which includes a freewheel activation device that allows independent second extension movement of the pull-out rail beyond the initial pivoting movement of the door, enabling greater object carrier movement without further door opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the driver bases are fastened close to the pivot axis of the door to accommodate narrow pantries, then the door can be opened within limited space, but the object carrier cannot be moved out to a significant extent

Engineering Contradiction:
Improveobject carrier movement distanceVSAvoidpath around pivot axis
Core Design Contradiction:
Volume of moving objectVSLength of stationary object

Solution Approach 1:

The pull-out movement is divided into two independent phases: first phase coupled to door opening (limited path), second phase independent freewheeling movement (extended path). This segmentation allows the object carrier to achieve greater total movement distance without requiring the driver bases to be positioned farther from the pivot axis.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling between door movement and object carrier movement is made dynamic rather than static. The freewheel mechanism allows the coupling to engage during door opening (first phase) and disengage automatically when the object carrier reaches a certain position (second phase), enabling extended movement without further door opening while adapting to narrow pantry constraints.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the object carrier is moved out significantly in narrow pantries, then accessibility is improved, but the door opening distance must be increased which is not feasible

Engineering Contradiction:
Improveobject accessibilityVSAvoiddoor opening distance
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The movement sequence is segmented into two independent phases: Phase 1 where door opening couples object carrier extraction (limited by pantry width), and Phase 2 where the object carrier continues moving out independently via freewheeling. This allows significant object accessibility without requiring proportionally large door opening distances.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The object carrier performs part of its own extraction work through the freewheeling mechanism. Once the door opening provides initial movement, the object carrier automatically continues its pull-out movement without requiring additional door opening effort, improving accessibility while limiting door travel distance.

Inventive Principle:
Principle #25Self-service

3Extent of automation

If a bidirectional coupling is used between door and object carrier, then automatic door closing is achieved, but the object carrier cannot be pulled out beyond the door opening path

Engineering Contradiction:
Improveautomatic door closingVSAvoidobject carrier pull-out distance
Core Design Contradiction:
Extent of automationVSVolume of moving object

Solution Approach 1:

The bidirectional coupling is applied only to the first phase of movement (door opening/closing), while the second phase (extended pull-out) uses unidirectional freewheeling. This segmentation allows automatic door closing functionality to be maintained while enabling the object carrier to travel beyond the door opening path during the second phase.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling mechanism transitions from bidirectional (during door operation) to unidirectional freewheeling (during extended pull-out). The freewheel allows rotation in the pull-out direction but prevents reverse rotation, enabling the object carrier to extend beyond door path while the door remains stationary, and automatically returning when pushed back.

Inventive Principle:
Principle #15Dynamics

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 allows for significant movement of object carriers and shelves out of the pantry, improving accessibility even in narrow cabinets by extending the pull-out path, enabling easy access and retraction of objects with bidirectional coupling and freewheel functionality.

Implementation Method 1

a freewheel (15) for the movable part (5) of the pull-out rail (2) opposite the door driver base (14), which allows a second pull-out movement in the pull-out direction (4) without further pivoting of the door (35)

Methodology Applied
Scientific EffectFreewheel mechanism: Ratchet

Data Source

PatentEP2976971B1Pull-out fitting with door coupling device and storage cupboard with such a pull-out fitting
Publication Date: 2021.04.07 VAUTH SAGEL HLDG GMBH & CO KG
  • EP2976971B1 patent drawingFigure 1
  • EP2976971B1 patent drawingFigure 2
  • EP2976971B1 patent drawingFigure 3(a)~3(b)

AI summary

A pull-out fitting (1) for a storage cupboard with a body having an opening and with a door that can be swung open about a pivot axis relative to the body, has a pull-out rail (2) with a movable part (5) to which an object carrier (6) is to be attached. and with a fixed part (3) on which the movable part (5) is movably mounted in a pull-out direction (4) and which is to be fastened to the body, and a door driver (13) with a driver base (13) to be fastened to the door 14). retracted position and a first extended position couples bidirectionally. The Zugdruckarm (16) is connected in series between the driver base (14) and the movable part (5) of the pull-out rail (2) with an activatable freewheel.