Dual-Plastic Expansion Anchor for Solid and Hollow Materials

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Solution Overview

Problem

Existing expansion anchors made of uniform plastic materials struggle to effectively anchor in both solid and hollow building materials, lacking versatility in expansion behavior.

Innovation Solution

The expansion anchor is designed with two base bodies made of different plastics, one reinforced with glass fibers, where the nut section is radially expandable and the expansion arms have varying behaviors to adapt to different anchoring bases, allowing for secure fastening in both solid and hollow materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a uniform plastic material is used for the expansion anchor, then the manufacturing process is simple and cost-effective, but the expansion behavior is insufficient for both solid and hollow building materials

Engineering Contradiction:
Improveexpansion behavior adaptabilityVSAvoidmaterial composition complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The expansion anchor uses a composite structure with two different plastic materials: a first plastic for the base body and a second plastic with higher elasticity for the expansion elements. This material combination enables the anchor to exhibit both structural stability and adaptive expansion behavior, allowing it to effectively anchor in both solid and hollow building materials while managing the complexity through a systematic multi-material design approach

Inventive Principle:
Principle #40Composite materials

2Force

If the expansion elements are made of highly elastic material, then the expansion force is increased, but the structural stability is reduced

Engineering Contradiction:
Improveexpansion forceVSAvoidstructural stability
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The expansion anchor applies local quality by assigning different material properties to different components: the base body uses a first plastic with structural stability for positional support, while the expansion elements use a second plastic with higher elasticity for generating expansion force. This localized material differentiation allows each component to optimize its function without compromising the overall system stability

Inventive Principle:
Principle #3Local quality

3Strength

If the anchor is designed for strong expansion, then the anchoring force in solid materials is improved, but the ability to adapt to hollow materials is reduced

Engineering Contradiction:
Improveanchoring forceVSAvoidmaterial compatibility
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The expansion anchor implements dynamics by designing expansion elements with higher elasticity that can adapt their behavior based on the anchoring conditions. In solid materials, the elastic expansion elements generate strong expansion forces for firm anchoring, while in hollow materials, the same elements can flex and conform to the cavity shape, providing versatile material compatibility while maintaining strong anchoring capability across different material types

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

The dual-plastic design ensures robust anchoring in diverse materials by expanding and bending to fit various conditions, providing a stable hold in both solid and hollow building structures.

Implementation Method 1

The expansion anchor consists of a first base body made of a first plastic and a second base body made of a second plastic. The two plastics differ, in particular in their type, color, strength, and/or fiber content, such as glass fibers, which serve in particular to reinforce the respective plastic.

Methodology Applied
Scientific EffectComposite materials: Composite Materials

Data Source

PatentEP4421332B1Plastic dowel
Publication Date: 2025.09.10 FISCHERWERKE ARTUR FISCHER GMBH & CO KG
  • EP4421332B1 patent drawingFigure 1~2
  • EP4421332B1 patent drawingFigure 3~4
  • EP4421332B1 patent drawingFigure 5~6

AI summary

The invention relates to an expansion anchor 1 made of plastic. In an expansion section 4, the expansion anchor 1 has two expansion arms 9 which extend parallel to a longitudinal axis L in a cantilevered manner and which are connected with their rear ends 11 to the head section 2.