Mechanical Drawer Ejector With Spring-Charged Closing Linkage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing ejection devices for movable furniture parts, such as drawers, require electrical energy for operation and are complex due to electrical wiring, making them inconvenient and energy-consuming.

Innovation Solution

A mechanical ejection device that uses a force transmission unit to charge the energy storage device of the retraction mechanism, allowing the retraction mechanism to move the furniture part into a closed position, and then the energy store of the ejection mechanism ensures the opening movement, eliminating the need for electrical energy and simplifying the system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an electrically operated ejector is used to move the furniture part from closed to open position, then the ejection function is achieved, but the device complexity increases due to electrical wiring and energy consumption occurs

Engineering Contradiction:
Improveejection functionVSAvoidelectrical wiring complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the electrical motor-driven ejector with a purely mechanical spring-based ejection system. The spring accumulator stores mechanical energy that is transferred through a ratchet mechanism and pawl to propel the furniture part outward, eliminating all electrical wiring and motors while maintaining the ejection function.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The spring accumulator automatically recharges during the closing movement of the furniture part through the ratchet mechanism, which allows unidirectional energy transfer. The system serves itself by converting the closing motion into stored spring energy, eliminating the need for external power sources or complex control systems.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If a mechanical retraction device is used to move the furniture part into closed position, then the retraction function is achieved, but additional mechanical components increase the device complexity

Engineering Contradiction:
Improveretraction functionVSAvoidmechanical components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the retraction and ejection functions into a single integrated mechanical system. The same spring accumulator that provides ejection force also powers the retraction through the ratchet mechanism, eliminating the need for separate motors or actuators for each function and reducing overall component complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring accumulator serves multiple functions: it stores energy for ejection, provides controlled retraction through the ratchet mechanism, and automatically recharges during the closing movement. This multi-functional design reduces the number of dedicated components needed for each specific function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If electrical energy is consumed for ejection operation, then the ejection function is reliable, but energy consumption increases operational costs

Engineering Contradiction:
Improveejection reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The spring accumulator is pre-charged with mechanical energy during the closing movement of the furniture part. This preliminary energy storage ensures that sufficient energy is available for reliable ejection without requiring continuous external power supply, eliminating ongoing energy consumption while maintaining operational reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The ratchet mechanism ensures continuous energy transfer from the closing movement to the spring accumulator, and subsequently from the spring to the ejection action. This continuous mechanical energy flow eliminates gaps in functionality and ensures reliable operation without intermittent power consumption.

Inventive Principle:
Principle #20Continuity of useful 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

The solution allows for convenient handling of furniture without electrical energy, reducing complexity and energy consumption, and ensures reliable operation of the ejection mechanism.

Implementation Method 1

an energy storage device of the retraction mechanism (73), by means of which the movable furniture part (2) can be moved into a closed position and held, an ejection mechanism that includes an ejector (13) that can be actuated by an energy storage device

Methodology Applied
Scientific EffectEnergy storage device: Mechanical Accumulator

Implementation Method 2

The energy store of the retraction mechanism is recharged during the ejection process. Due to the remaining component of the retraction force store of the retraction mechanism

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 3

the power transmission unit is designed as a lever mechanism. In this case, a lever can be provided which can be moved on one side with the ejector and on the opposite side along a run-up slope. The lever can bring about a translation of the force ratios in that the lever arms are of different lengths

Methodology Applied
Scientific EffectLever mechanism: Lever

Implementation Method 4

The closed position is defined by elastic stops that ensure the release path. When triggered in the closing direction, these stops are compressed and the triggering mechanism is activated

Methodology Applied
Scientific EffectElastic stops: Elasticity

Implementation Method 5

wheels, in particular toothed wheels or friction wheels, are provided as the power transmission unit, and one wheel is coupled to the ejector via a toothed rack or a friction rod. As a result, a linear movement of the furniture part can be converted into a rotary movement of the wheels

Methodology Applied
Scientific EffectFriction wheel: Friction

Implementation Method 6

wheels, in particular toothed wheels or friction wheels, are provided as the power transmission unit

Methodology Applied
Scientific EffectGear: Gear

Data Source

PatentEP2364614B1Opening device for movable parts of furniture
Publication Date: 2015.07.29 PAUL HETTICH GMBH & CO KG
  • EP2364614B1 patent drawingFigure 1
  • EP2364614B1 patent drawingFigure 2
  • EP2364614B1 patent drawingFigure 3A~4

AI summary

The device (74) has an ejecting mechanism comprising an ejector (13) that brings a movable furniture part i.e. drawer (2), from a closing position into an opened position. A releasing mechanism controls loading and unloading of a force storage unit i.e. spring (14). A force storage unit of a feeding mechanism partially loads the force storage unit of the release mechanism still reaching the closed position by a force transfer unit e.g. toothed wheel or lever gear (8). The toothed wheel is coupled with the ejector by a toothed rod or a friction rod.