Self-closing device and drawer runner

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Solution Overview

Problem

Existing self-closing mechanisms for pull-out slides lack sufficient damping forces to slow down the closing movement and have design limitations that make them complex and difficult to maintain, such as requiring complete disassembly for spring replacement.

Innovation Solution

A compact self-closing mechanism with a spiral spring that surrounds the damper housing, allowing for easy spring replacement and providing sufficient pretensioning forces, featuring a pivotably mounted driver and a fluid damper for high damping capabilities, integrated within a C-shaped guide rail system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a spring is arranged inside a damper housing, then the design becomes compact, but the spring cannot be replaced without completely dismantling the damper

Engineering Contradiction:
Improvespace utilizationVSAvoidspring replacement
Core Design Contradiction:
Volume of moving objectVSEase of repair

Solution Approach 1:

The spring and damper are separated into independent components. The spring is arranged outside the damper housing, allowing it to be replaced independently without dismantling the damper. This segmentation resolves the contradiction by enabling easy maintenance while maintaining compact overall design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring is extracted from the damper housing and positioned separately. This allows the spring to be accessed and replaced independently, eliminating the need to completely dismantle the damper for spring replacement, thus improving ease of repair.

Inventive Principle:
Principle #2Taking out (Extraction)

2Force

If a self-closing mechanism is provided at the end of a guide rail, then closing force is provided, but no damping forces can be applied to slow down the closing movement

Engineering Contradiction:
Improveclosing forceVSAvoidimpact noise
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The spring mechanism and damper are combined into a single self-closing mechanism assembly. The spring provides the closing force while the damper simultaneously provides damping forces to slow down the closing movement, eliminating impact noise. This merging resolves the contradiction by integrating both force generation and damping functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The damper acts as an intermediary between the spring's closing force and the rail movement. It mediates the force transmission by providing controlled resistance, slowing down the closing movement and preventing impact noise while maintaining the closing function.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Force

If a compression spring is used, then sufficient pretensioning forces can be provided, but lateral breaking out requires guide means

Engineering Contradiction:
Improvepretensioning forceVSAvoidguide means
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

Instead of using a compression spring that requires guide means to prevent lateral breaking out, the invention uses a tension spring. The tension spring is arranged to be pulled rather than compressed, which eliminates lateral breaking out and removes the need for guide means, thus reducing device complexity while maintaining sufficient pretensioning force.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The spring type is changed from compression to tension. This parameter change fundamentally alters the spring's behavior: tension springs do not exhibit lateral breaking out, eliminating the need for guide means and reducing overall device complexity while still providing adequate pretensioning forces.

Inventive Principle:
Principle #35Parameter changes

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 provides a simple, compact, and effective self-closing mechanism that applies sufficient forces to slow down the rail's closing movement, is easy to maintain, and optimizes installation space, ensuring quiet operation and reliable function.

Implementation Method 1

a spiral spring (9) that surrounds the damper housing (80)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a fluid damper (8) for high damping capabilities

Methodology Applied
Scientific EffectFluid damper: Viscous Damping

Data Source

PatentEP3429430B1Self-closing device and drawer runner
Publication Date: 2020.01.29 PAUL HETTICH GMBH & CO KG
  • EP3429430B1 patent drawingFigure 1~2
  • EP3429430B1 patent drawingFigure 3
  • EP3429430B1 patent drawingFigure 4

AI summary

The invention relates to a self-closing device (5), in particular for drawer runners (1), comprising a housing (6), in which a guide (61) is provided for a linearly moveable slider (7) and a guide path (63) is provided for a catch (11) connected to the slider (7), wherein the catch (11) can be coupled to an activator (10) and a damper (8) having a damper housing (80) and a piston rod (81) is provided between the housing (6) and the slider (7), wherein a spring (9) is arranged around the damper (8), by means of which the slider (7) is pretensioned on the housing (6) in a closing position. The invention also relates to a drawer runner (1) having a self-closing device (5).