Segmented Dowel With Separate Fastening Claws for Thin-Panel Furniture

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Solution Overview

Problem

Existing dowels for furniture fittings face challenges in providing a strong hold in various materials, especially in thin-walled materials, due to their size and design limitations, and often require complex components and assembly processes.

Innovation Solution

A compact dowel design featuring a dowel sleeve with separate guides and locking means for fastening claws, which can be independently connected to the sleeve, allowing for radial expansion and a secure hold in materials, using a minimal number of components and enabling pre-assembly with a tension element like a screw.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional dowel designs are used, then the dowel can provide a secure hold in materials, but the dowel dimensions become large and cannot be used with thin-walled furniture materials

Engineering Contradiction:
Improvehold strengthVSAvoiddowel length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The dowel is divided into separate components: a dowel sleeve and multiple independent fastening claws that can be inserted separately into the sleeve. This segmentation allows each component to be optimized independently, enabling a compact overall structure that fits thin-walled materials while maintaining effective holding surfaces when expanded

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fastening claws are designed to be inserted into and nested within the dowel sleeve in a compact state before expansion. This nesting arrangement minimizes the insertion length requirement, allowing the dowel to be installed in thin-walled furniture materials while still providing sufficient expansion space for secure holding

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of moving object

If multiple components are used to achieve compact design, then the dowel can fit thin panels, but the assembly process becomes more complex

Engineering Contradiction:
Improvedowel lengthVSAvoidnumber of components
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

Multiple fastening claws are combined within a single dowel sleeve structure, with each claw having its own guide and locking means integrated into the sleeve. This merging approach consolidates what could be multiple separate components into a unified assembly that requires fewer parts and simplifies the installation process

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The dowel sleeve serves multiple functions simultaneously: it acts as a guide for inserting fastening claws, provides locking means to secure the claws in place, and serves as the expanding structure that provides the holding function. This multi-functionality reduces the need for separate components and simplifies the overall design

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

3Ease of operation

If separate guides and locking means are provided for each fastening claw, then the fastening claws can be independently connected to the dowel sleeve, but the manufacturing complexity increases

Engineering Contradiction:
Improveassembly easeVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The guides and locking means are pre-formed as integral features of the dowel sleeve during the molding process, rather than being added as separate components. This preliminary action during manufacturing simplifies the overall production process while still providing the necessary guidance and locking functions for easy assembly of the fastening claws

Inventive Principle:
Principle #10Preliminary 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 enables a cost-effective, compact dowel with small dimensions suitable for thin panels, providing a secure hold in different materials by allowing the dowel to expand radially and penetrate materials effectively, while minimizing loose parts and assembly complexity.

Implementation Method 1

an expansion element that can be moved axially in the dowel sleeve for radially expanding the at least one fastening claw and the dowel sleeve

Methodology Applied
Scientific EffectRadial expansion:

Implementation Method 2

the guide performing a lateral centering of the fastening claw used

Methodology Applied
Scientific EffectLateral centering:

Implementation Method 3

locking means are provided which hold the fastening claw used in the guide on the dowel sleeve

Methodology Applied
Scientific EffectMechanical locking: Mechanical Fastener

Data Source

PatentEP3622142B1Dowel for fastening fitting parts
Publication Date: 2021.09.29 JULIUS BLUM GMBH
  • EP3622142B1 patent drawingFigure 1
  • EP3622142B1 patent drawingFigure 2a~2b
  • EP3622142B1 patent drawingFigure 3a~3b

AI summary

Dowel for fastening fitting parts of pieces of furniture, comprising: a dowel sleeve (1); at least one fastening claw (2) which is separate from the dowel sleeve (1); a spreading element (3) which is movable axially in the dowel sleeve (1) and intended for radially spreading the at least one fastening claw (2) and the dowel sleeve (1), wherein the dowel sleeve (1) has a guide (9) which laterally guides a retaining portion (2a) of the fastening claw (2), and wherein latching means (12, 13) are provided which retain the fastening claw (2), which is inserted into the guide (9), on the dowel sleeve (1), preferably with play, and wherein the spreading element (3) can be connected to at least one fastening claw (2), preferably to all fastening claws (2).