Expansion Anchor Angled Abutment Edge for Progressive Sleeve Resistance

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Solution Overview

Problem

Existing expansion anchors face challenges in achieving satisfactory performance while minimizing manufacturing effort.

Innovation Solution

The expansion anchor features an angled transition edge between the recess floor and the sleeve abutment wall, with a lead angle between 4° and 30°, which allows for progressive axial abutment and increased internal resistance during expansion, thereby enhancing anchoring performance with reduced manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transition edge is arranged perpendicular to the longitudinal axis, then the abutment area is maximized, but the manufacturing precision requirements increase and performance is insufficient

Engineering Contradiction:
Improveanchoring performanceVSAvoidgeometry complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The transition edge is designed with an asymmetric angled geometry rather than a symmetric perpendicular arrangement. The lead angle α creates an asymmetric profile that provides both adequate abutment area and improved anchoring performance through the angled configuration, resolving the contradiction between performance and geometric simplicity.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The perpendicular arrangement parameter is changed to an angled arrangement with lead angle α between 4° and 30°. This parameter modification transforms the transition edge geometry to achieve progressive axial abutment and enhanced internal resistance while maintaining manufacturability, thus improving anchoring performance without excessive complexity.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If the transition edge has a large lead angle, then the abutment area increases, but the manufacturing effort increases due to larger dimensions

Engineering Contradiction:
Improveabutment areaVSAvoidmanufacturing effort
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The lead angle α is optimized within the range of 4° to 30° to achieve the optimal balance between abutment area and manufacturing effort. This parameter optimization ensures sufficient abutment area for anchoring performance while keeping the dimensions manageable for cost-effective manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The transition edge provides sufficient abutment area through the angled geometry without requiring excessive dimensions. The lead angle α ensures that the abutment area is adequate for performance requirements while avoiding overly large dimensions that would increase manufacturing complexity and cost.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of manufacture

If the transition edge is perpendicular to the longitudinal axis, then the manufacturing is simpler, but the internal resistance increase is insufficient

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidinternal resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The perpendicular symmetric arrangement is replaced with an asymmetric angled transition edge at lead angle α. This asymmetric geometry creates a progressive abutment mechanism that generates sufficient internal resistance during expansion while remaining compatible with standard manufacturing processes.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The transition edge geometry enables a dynamic progressive abutment mechanism during expansion. As the expansion sleeve moves axially, the angled transition edge progressively engages, creating a gradual increase in internal resistance that enhances anchoring strength while maintaining manufacturing simplicity.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4560152A1Expansion anchor with angled abutment wall transition edge
Publication Date: 2025.05.28 HILTI AG
  • EP4560152A1 patent drawingFigure 1~5
  • EP4560152A1 patent drawingFigure 3~4
  • EP4560152A1 patent drawing

AI summary

Expansion anchor comprising an anchor bolt having a longitudinal axis, an expansion sleeve surrounding the anchor bolt, and an expansion body located in a front region of the anchor bolt, which has a converging zone for expanding the expansion sleeve. The expansion body is provided with an abutment wall recess. The abutment wall recess is delimited by a sleeve abutment wall that, axially, faces the expansion sleeve so as to provide an abutment for the expansion sleeve when the expansion sleeve is moved axially towards the sleeve abutment wall. The abutment wall recess is further delimited by a recess floor. A transition edge is formed between the recess floor and the sleeve abutment wall. The transition edge extends at a lead angle α. At least in a section of the transition edge, the following holds for the lead angle α: 4° ≤ α ≤ 30°.