Welded Expansion Anchor Assembly for Custom Rod Lengths

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Solution Overview

Problem

Existing expansion anchors require different lengths to secure objects to concrete, leading to inventory management challenges, environmental waste, and safety concerns due to excess protruding rod lengths.

Innovation Solution

A method of welding a conical expansion part to a threaded rod of customized length, allowing on-demand production of expansion anchors, with welding flash contained within the gap between the parts to avoid protrusion and reduce manufacturing steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If expansion anchors are stocked in different lengths to meet various object thicknesses, then adaptability to different applications is improved, but inventory management complexity increases and raw material waste occurs due to overstocking

Engineering Contradiction:
Improveadaptability to different object thicknessesVSAvoidinventory management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The expansion anchor is divided into two separable components: a threaded rod and an expansion portion. The threaded rod can be produced in standard lengths and stored, while the expansion portion is attached as needed. This segmentation allows the threaded rod to be reused across different anchor lengths, reducing inventory complexity while maintaining adaptability to various object thicknesses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention enables dynamic customization of anchor length by welding different expansion portions to standard threaded rods on-demand. Rather than maintaining static inventory of all possible lengths, the system dynamically creates the specific length needed for each application, reducing overstocking and waste while maintaining versatility.

Inventive Principle:
Principle #15Dynamics

2Reliability

If threaded rod length is increased to ensure sufficient embedment depth, then anchoring reliability is improved, but safety hazards increase due to excess protruding length

Engineering Contradiction:
Improveanchoring reliabilityVSAvoidsafety hazards from protruding rod
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By separating the threaded rod from the expansion portion, the system allows precise control over the final anchor length. The threaded rod can be cut to exact dimensions needed for reliable embedment, preventing excessive protrusion that creates safety hazards while maintaining sufficient length for anchoring reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention enables precise adjustment of the threaded rod length parameter to match the specific requirements of each application. By producing anchors with customized lengths rather than using fixed standard lengths, the system optimizes the balance between embedment depth for reliability and protrusion length for safety.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If expansion portion is welded to threaded rod after cutting, then manufacturing flexibility is improved, but manufacturing complexity increases due to additional welding step

Engineering Contradiction:
Improvemanufacturing flexibility for customized lengthsVSAvoidmanufacturing process simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The expansion anchor is manufactured as separate components (threaded rod and expansion portion) that are welded together. This segmentation allows the threaded rod to be produced in standard lengths through simple cutting, while the expansion portion is attached in a separate welding step, enabling manufacturing flexibility without requiring complex integrated production processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The threaded rod is cut to standard lengths in advance before the expansion portion is welded to it. This preliminary action simplifies the manufacturing process by separating the cutting operation from the welding operation, allowing each component to be prepared independently and then assembled, thereby reducing overall manufacturing complexity while maintaining flexibility.

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

Customized expansion anchors minimize excess rod length, optimize inventory management, and enhance environmental sustainability by reducing raw material waste.

Implementation Method 1

A method of welding a conical expansion part to a threaded rod of customized length

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4425003B1Expansion anchor and method of making an expansion anchor
Publication Date: 2026.03.04 BLACK & DECKER CORP
  • EP4425003B1 patent drawingFigure 1~3
  • EP4425003B1 patent drawingFigure 4~6
  • EP4425003B1 patent drawingFigure 7

AI summary

A method of making an expansion anchor comprising the steps of: providing a metal rod having a thread along at least part of its outer surface; cutting the metal rod to obtain a required length of metal rod; welding an expansion section to an end of the obtained length of metal rod; and providing an expansion sleeve which in use interacts with the expansion section for increasing the expansion sleeve diameter; wherein the expansion section is integral with a spacer section and the step of welding involves welding an end of the spacer section to the threaded rod. An expansion anchor comprising a threaded rod part, an expansion section welded to an end of the rod part and an expansion sleeve which in use interacts with the expansion section for increasing the diameter of the expansion sleeve, wherein the expansion section is integral with a spacer section and an end of the spacer section is welded to the threaded rod part.