Dual-Material Expansion Anchor Collar for Anti-Spinning Setting

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Solution Overview

Problem

Existing expansion anchors face challenges in balancing the collapsible, anti-spinning, and setting functions due to the limitations of using a single material, which affects their performance in securing heavy loads to concrete surfaces.

Innovation Solution

The use of a collar composed of two materials with different hardness levels, where the inner part is made of a harder material for collapsible function and the outer part is made of a softer material for anti-spinning and setting functions, achieved through double shot molding or separate assembly, allowing for improved deformation and resistance to torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single material is used for the collar to fulfill collapsible, anti-spinning, and setting functions, then the device complexity is reduced, but the performance balance among the three functions deteriorates

Engineering Contradiction:
Improvecollar structureVSAvoidperformance balance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The collar is constructed using composite materials with different hardness levels - a harder inner material for collapsible function and a softer outer material for anti-spinning and setting functions. This composite structure enables the single collar component to simultaneously fulfill all three required functions with balanced performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different regions of the collar are assigned different material properties - the inner part uses harder material while the outer part uses softer material. This local differentiation allows each region to optimize its specific function while maintaining overall structural integrity.

Inventive Principle:
Principle #3Local quality

2Strength

If a harder material is used for the collar to improve collapsible function, then the pre-tension capability is improved, but the anti-spinning and setting functions deteriorate

Engineering Contradiction:
Improvepre-tension capabilityVSAvoidanti-spinning and setting
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The collar combines harder inner material for pre-tension capability with softer outer material for anti-spinning and setting functions, resolving the contradiction between strength and ease of operation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The harder material is localized to the inner region where pre-tension is needed, while the softer material is applied to the outer region where anti-spinning and setting operations occur, allowing each function to operate optimally.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If a softer material is used for the collar to improve anti-spinning function, then the ease of operation is improved, but the collapsible function deteriorates

Engineering Contradiction:
Improveanti-spinning functionVSAvoidcollapsible function
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The collar uses composite materials where the softer outer material provides anti-spinning functionality while the harder inner material maintains the necessary collapsible strength and pre-tension capability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The softer material is applied locally to the outer surface where anti-spinning contact occurs, while the harder material remains in the inner structure where collapsible function and pre-tension are required.

Inventive Principle:
Principle #3Local quality

4Ease of operation

If the outer diameter of the collar is increased to improve anti-spinning function, then the contact face area is increased, but the ease of assembly deteriorates

Engineering Contradiction:
Improveanti-spinning functionVSAvoidease of assembly
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The softer outer material allows for adequate anti-spinning contact area with a more reasonable outer diameter, as the softer material can deform to increase effective contact area without requiring a larger overall collar size.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Changing the material hardness parameter of the outer collar material allows for optimization of the outer diameter dimension, reducing it while maintaining adequate anti-spinning contact area through material deformation.

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

This dual-material approach enhances the anchor's ability to securely fasten heavy loads by preventing spinning and ensuring easy assembly, while maintaining structural integrity under high torque, thus providing a balanced performance in collapsible, anti-spinning, and setting functions.

Implementation Method 1

the outer part is made of a softer material for anti-spinning and setting functions

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

the inner part is made of a harder material for collapsible function

Methodology Applied
Scientific EffectCompression resistance: Compression

Implementation Method 3

The use of a collar composed of two materials with different hardness levels... allowing for improved deformation and resistance to torque

Methodology Applied
Scientific EffectStress distribution: Stress Relaxation

Data Source

PatentEP4028671B1Expansion anchor
Publication Date: 2024.08.14 HILTI AG
  • EP4028671B1 patent drawingFigure 1~3b
  • EP4028671B1 patent drawingFigure 4a~5b

AI summary

An expansion anchor, comprises a bolt, a spacer sleeve, an expansible sleeve, an expanding member, and a collar, being arranged between the expansible sleeve and the spacer sleeve and having the form of a ring-like body, the bolt inserting into the spacer sleeve, the collar and expansible sleeve in sequence, and thread connected to the cone at its leading end, to thereby draw the expanding member into the expansible sleeve and expand radially; said collar is formed by a first material and a second material with different hardness. This expansion anchor can perfectly balance the collapsible function, the anti-spinning and setting functions of the collapsible part.