Borehole Thread Grooving for Deep Mineral Anchor Fastening

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Solution Overview

Problem

Existing anchoring technologies in mineral substrates, such as concrete, face challenges in achieving reliable high load levels and efficient setting processes, particularly in subsequent reinforcement and forming overlapping joints, which often require complex adhesive or bonding processes.

Innovation Solution

A system and method for fastening an anchor in a mineral substrate using a grooving tool to create an internal thread in the borehole, allowing for the use of anchors with significantly longer thread sections relative to the borehole diameter, and enabling easy and safe setting without the need for specialized personnel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive or bonding processes are used for fastening anchor rods in mineral substrate, then reliable high load levels can be achieved, but the process becomes complex and time-consuming

Engineering Contradiction:

Improveload levelVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the chemical bonding process (adhesive/mortar) with a mechanical threading process. A grooving tool with cutting edges is screwed into the borehole to mechanically cut internal threads directly into the mineral substrate, eliminating the need for adhesive application and hardening time while providing reliable mechanical anchoring through thread engagement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the anchoring mechanism from chemical bonding to mechanical thread engagement by modifying the substrate surface through grooving. The grooving tool creates threaded surfaces that allow direct mechanical fastening of the anchor rod, fundamentally changing the interaction parameter from adhesive bonding strength to thread shear strength and engagement depth.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If adhesive or bonding processes are used for fastening anchor rods, then reliable anchoring is achieved, but the setting time increases significantly

Engineering Contradiction:

Improveanchoring reliabilityVSAvoidsetting time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent eliminates the time-consuming adhesive application and hardening process by substituting it with immediate mechanical thread cutting. The grooving tool creates functional threads in real-time during installation, allowing the anchor rod to be fastened immediately without waiting for adhesive curing, thus reducing setting time from hours to minutes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If screw anchors with self-tapping threads are used, then the grooving process is integrated, but the effective anchoring depth is limited to eight times the borehole diameter

Engineering Contradiction:

Improvesetting easeVSAvoidanchoring depth

Core Design Contradiction:

Ease of operationVSLength of stationary object

Solution Approach 1:

The grooving tool performs preliminary action by pre-cutting the internal threads into the borehole wall before the anchor rod is inserted. This preliminary threading creates a ready-received mechanical interface that allows the anchor rod to engage fully along its length without self-tapping limitations, enabling anchoring depths exceeding eight times the borehole diameter while maintaining ease of installation.

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 proposed solution allows for simple, quick, and reliable anchoring with a high load level, reducing the risk of errors and costs associated with complex bonding processes, and enabling the use of anchors of practically any length.

Implementation Method 1

a grooving tool for grooving internal threads in the borehole

Methodology Applied

Scientific EffectMechanical cutting/thread forming:

Implementation Method 2

The anchor (16) has an external thread (18), which is suitable for being screwed into the internal thread (14)

Methodology Applied

Scientific EffectThread engagement:

Data Source

PatentUS12234851B2System for securing an anchor in a mineral substrate

Publication Date: 2025.02.25 LUDWIG HETTICH

AI summary

Disclosed herein is a system for fastening an anchor in a borehole in a mineral substrate, in particular concrete, mortar or masonry, comprising an anchor having a core section and a thread section, and a grooving tool for grooving an internal thread in the borehole, the grooving tool comprising the following: a base body having a leading and a trailing end, a force application device being provided, via which a torque for screwing the grooving tool into the borehole and for grooving the thread is transmitted to the base body, the base body having an outer surface on which a grooving thread is formed, which is suitable for grooving the internal thread into the wall of the borehole, the following applying to the ratio of the length heff of the thread section of the anchor and the nominal diameter db of the borehole: heff/db≥10.0, preferably ≥12.0, particularly preferably ≥15.0, and in particular ≥30.0.