Doubling-up fitting and associated assembly having two doubled-up plates

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Solution Overview

Problem

Existing double fittings for furniture panels require the use of an impact tool to anchor the fitting housing in a blind hole, making installation cumbersome and tool-dependent.

Innovation Solution

A double fitting with a clamp element, rotatably mounted expansion disc, and adjusting disk that allows for two-dimensional adjustment and manual insertion into a hole, utilizing angled clamp arms and a stepped disk design to spread radially and lock in place without the need for tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional doubling fitting with a ring-shaped fitting housing is used, then the front panel can be firmly anchored in the furniture carcass, but the fitting housing cannot be inserted into the blind hole by hand and must be driven in with a tool

Engineering Contradiction:
ImproveEase of insertionVSAvoidInsertion mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The clamping element transitions from a compressed state during insertion to an expanded state for anchoring. The clamping arms are initially compressed together to reduce the profile, allowing hand insertion into the blind hole. After insertion, the clamping arms are spread apart to expand the profile, firmly anchoring the fitting in the hole without requiring impact tools.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clamping arms are nested together in a compressed configuration to reduce the overall width of the clamping element, enabling it to pass through the opening into the blind hole. Once positioned, the arms are deployed outward from the nested state to engage with the blind hole walls, providing secure anchoring.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the clamping arms are spread radially outwards to anchor in the blind hole, then firm fixation is achieved, but the installation process becomes more complex

Engineering Contradiction:
ImproveAnchoring reliabilityVSAvoidInstallation simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The clamping arms are pre-configured in a compressed state that allows easy insertion. After the clamping element is positioned in the blind hole, the spreading action is performed to deploy the arms for anchoring. This preliminary compression configuration simplifies the installation process by separating the insertion and anchoring steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The clamping element automatically anchors itself in the blind hole through the spreading of clamping arms. The design enables the fitting to secure itself without requiring additional tools or complex installation procedures. The clamping arms engage with the blind hole walls through their own geometric configuration when spread apart.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If a larger clear opening diameter of the fitting housing is used, then two-dimensional adjustment of the front panel is enabled, but the fitting housing cannot be manually inserted into the blind hole

Engineering Contradiction:
ImproveAdjustment rangeVSAvoidManual insertability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The profile of the clamping element dynamically changes during installation. In the compressed state, the width is reduced to enable manual insertion into the blind hole despite the large opening diameter requirement for adjustment. After insertion, the element expands to its full width, providing the necessary large opening diameter for two-dimensional adjustment of the front panel.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clamping element utilizes the third dimension (depth) to resolve the contradiction. By compressing the clamping arms together along the depth dimension, the width dimension is reduced to fit through the opening. Once inserted, the arms are deployed in the width dimension to provide the large opening diameter needed for adjustment, effectively using dimensional transformation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enables easy, tool-free installation and secure anchoring of furniture panels, allowing for ±2mm adjustment and firm fixation without the use of impact tools.

Implementation Method 1

a rotatably mounted spreading disc arranged in the clamping element between the clamping base and the free clamping ends, with several outer contour sections, each cooperating with a clamping arm, which in a starting rotational position of the spreading disc spread the free clamping ends less radially outwards than in a final rotational position

Methodology Applied
Scientific EffectMechanical expansion: Mechanical Force

Implementation Method 2

an adjusting disc with a thread arranged in the receptacle of the spreading disc, wherein the outer diameter of the adjusting disc is smaller than the diameter of the recess of the spreading disc and larger than the opening diameter of the disc opening

Methodology Applied
Scientific EffectThreaded fastening: Screw

Data Source

PatentEP4240980B1Doubling-up fitting and associated assembly having two doubled-up plates
Publication Date: 2024.10.23 HAFELE BERLIN GMBH & CO KG
  • EP4240980B1 patent drawingFigure 1a~2
  • EP4240980B1 patent drawingFigure 3

AI summary

A doubling-up fitting (1) according to the invention comprises: - a clamp element (10), which has a clamp bottom (11) and at least two clamp arms (12), which clamp arms rise up from the clamp bottom (11) at respective ends of the clamp bottom, and the free clamp ends (13a, 13b) of which clamp arms are bent inward and extend over the clamp bottom (11); - a rotatably mounted spreading disk (20) disposed in the clamp element (10) between the clamp bottom (11) and the free clamp ends (13a, 13b), the spreading disk having a disk opening (21), which leads into a recess (22) in the spreading disk (20), which recess is open toward the clamp bottom (11) and the diameter (D2) of which recess is greater than the opening diameter (D1) of the disk opening (21), and the spreading disk having a plurality of outer contour portions (23), which each interact with one of the clamp arms (12) and which spread the free clamp ends (13a, 13b) radially outward less far in an initial rotational position of the spreading disk (20) than in a final rotational position; and - an adjusting disk (30), which is disposed in the receptacle (22) of the spreading disk (20) and has a screw thread (31); wherein the outside diameter (d1) of the adjusting disk (30) is less than the diameter (D2) of the recess (22) in the spreading disk (20) and greater than the opening diameter (D1) of the disk opening (21).