Furniture Drive Housing With Switchable Ejection and Retraction

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Solution Overview

Problem

Existing drive devices for movable furniture parts often require separate housings for retraction and ejection devices, leading to increased manufacturing and assembly costs, and are inefficient in handling both opening modes by pulling or pressing without proper locking mechanisms.

Innovation Solution

A drive device with a retraction operating mode and an ejection and retraction operating mode, where the ejection device is coupled to the retraction device via a push element and a coupling element with bayonet-like coupling parts, allowing for independent operation of the ejection and retraction functions within a common housing, enabling flexible attachment to furniture parts with or without handles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ejection device and retraction device are arranged in separate housings, then each device can be optimized independently, but the manufacturing costs and assembly costs increase

Engineering Contradiction:
Improvedevice optimizationVSAvoidmanufacturing costs and assembly costs
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines the ejection device and retraction device into a single common housing, integrating two previously separate functions into one unified structure. This merging eliminates the need for separate housings, reducing manufacturing steps and assembly operations while maintaining the functional independence and optimization capabilities of each device through internal separation mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If the ejection device is always unlocked when opening by pulling, then the coupling device moves loosely, but the ejection force accumulator relaxes and must be tensioned again

Engineering Contradiction:
Improveopening by pullingVSAvoidre-tensioning time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent implements a dynamic locking mechanism where the locking pin can be selectively locked or unlocked based on the operating mode. In the first operating mode (opening by pulling), the locking pin remains locked to maintain ejection force accumulator tension while allowing controlled movement. In the second operating mode (opening by overpressing), the locking pin unlocks to allow the ejection device to function. This dynamic state change eliminates the need for re-tensioning.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If a common housing is used for both devices, then manufacturing costs are reduced, but the devices may interfere with each other's operation

Engineering Contradiction:
Improvemanufacturing costsVSAvoiddevice operation independence
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the common housing into distinct functional zones for the ejection device and retraction device. Internal partitions and separate mounting structures create independent operational spaces within the unified housing, preventing mechanical interference between the two devices while maintaining cost-effective manufacturing through a single housing structure.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If the locking pin is released when opening by pulling, then the movable furniture part can be opened, but the locking pin must be locked again and the ejection force accumulator re-tensioned

Engineering Contradiction:
Improveopening by pullingVSAvoidlocking and tensioning mechanisms
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent employs a dynamic control system where the locking pin's state (locked or unlocked) is determined by the detected operating mode. The system automatically maintains the locked state during pull-opening operations, preserving ejection force accumulator tension without requiring manual intervention for re-locking or re-tensioning. This dynamic behavior reduces the effective complexity by eliminating redundant locking cycles.

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 a compact, cost-effective drive device that can be preassembled on furniture parts and activated in different modes based on handle presence, ensuring proper locking and operation without unnecessary ejection function activation, thus reducing manufacturing costs and enhancing operational efficiency.

Implementation Method 1

a first spring (ejection force accumulator) for storing an ejection force

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

first spring (ejection force accumulator) for storing an ejection force

Methodology Applied
Scientific EffectMechanical Accumulator: Mechanical Accumulator

Implementation Method 3

a second spring (retraction force accumulator) for storing a retraction force

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 4

second spring (retraction force accumulator) for storing a retraction force

Methodology Applied
Scientific EffectMechanical Accumulator: Mechanical Accumulator

Data Source

PatentEP3319483B1Drive device for a movable furniture part
Publication Date: 2019.09.18 JULIUS BLUM GMBH
  • EP3319483B1 patent drawingFigure 1
  • EP3319483B1 patent drawingFigure 2
  • EP3319483B1 patent drawingFigure 3

AI summary

The invention relates to a drive device (1) for a movable furniture part (2), in particular a drawer, comprising a housing (6, 7), an ejection device (3) which is arranged in the housing (6, 7) for ejecting the movable furniture part (2) out of a closed position (SS) into an open position (OS), and a retracting device (4) which is arranged in the same housing (6, 7) for retracting the movable furniture part (2) out of an open position (OS) into the closed position (SS). The drive device (1) has a first operating mode (B1) and a second operating mode (B2). In the first operating mode (B1), only the retracting device (4) is operative while opening and closing the movable furniture part (2), and in the second operating mode (B2), both the ejection device (3) and the retracting device (4) are operative while opening and closing the movable furniture part (2).