Gear-Linked Ejector Lever Layout for Compact Drawer Depth

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Solution Overview

Problem

Existing ejection devices for furniture and drawers face challenges in minimizing overall depth and length, especially when not in use, as they often require more space due to the design of the lever arm and extension leg, which hinders optimal space utilization.

Innovation Solution

The ejection device employs a gear mechanism to pivot the extension leg relative to the lever arm, allowing them to overlap in the non-functional position, achieving the smallest possible dimensions and maintaining contact with the furniture part over a longer path during ejection, with adjustable gear parts for varying forces and torques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the extension leg is pivoted relative to the lever arm by contacting an abutment against the force of a leg spring, then the ejection device can return to non-functional position, but the overall depth and length cannot be minimized

Engineering Contradiction:
Improvereturn mechanismVSAvoidoverall depth
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent replaces the spring-based mechanical return mechanism with a gear-based mechanical advantage system. The gear mechanism, driven by the drive device, provides both the ejection force and the return function through controlled pivoting, eliminating the need for separate spring components and abutments that increase depth.

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

Solution Approach 2:

The extension leg is designed to nest within or alongside the lever arm when not in use. Through the gear mechanism, the extension leg pivots to a position where it overlaps with the lever arm, minimizing the overall depth and length of the ejection device in its non-functional state.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of stationary object

If the lever arm and extension leg are designed to overlap in non-functional position, then the smallest overall depth is achieved, but the mechanism becomes more complex

Engineering Contradiction:
Improveoverall depthVSAvoidgear mechanism
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The gear mechanism serves multiple functions simultaneously: it provides the driving force for ejection, controls the pivoting of the extension leg, enables the overlapping compact position, and facilitates the return to functional position. This multi-functionality justifies the added mechanical complexity by consolidating what would otherwise require separate systems.

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

3Length of stationary object

If the extension leg is kept short to minimize depth, then the overall depth is reduced, but the ejection path coverage is limited

Engineering Contradiction:
Improveoverall depthVSAvoidejection path
Core Design Contradiction:
Length of stationary objectVSLength of moving object

Solution Approach 1:

The extension leg is designed with dynamic pivoting capability through the gear mechanism. Although physically short to minimize depth, it can pivot through a range of angles during operation, effectively extending its reach and coverage along the ejection path. The dynamic movement compensates for the reduced static length.

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 design achieves the smallest overall depth and length, ensuring a compact construction while maintaining effective ejection performance, with adjustable transmission options for different drawer dimensions and forces.

Implementation Method 1

the extension leg is pivoted exclusively via a gear which is mounted on the extension leg on the one hand and on the other hand acts on the lever arm

Methodology Applied
Scientific EffectGear mechanism: Gear

Implementation Method 2

a drive device (13) in the form of a torsion spring, which acts on the lever arm (3) in the region of the pivot bearing (10)

Methodology Applied
Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentEP2380459B1Ejector device
Publication Date: 2015.01.28 PAUL HETTICH GMBH & CO KG
  • EP2380459B1 patent drawingFigure 1~2
  • EP2380459B1 patent drawingFigure 3~4

AI summary

The expulsion device has an expulsion lever (2) having a contact surface. The expulsion lever is mounted in a pivoting manner at a supporting part (1) from a non-use position into a use position. An extension blade (4) and a lever arm (3) are connected to each other in a motion-dependent manner by a gear (5) for relative deviation to each other.