Thread Tapping Screw Wear Indicator Identification

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Solution Overview

Problem

Self-tapping screws, particularly those used in concrete, face challenges in assessing wear and reusability due to potential misinterpretation of thread damage as wear indicators, leading to uncertain load-bearing properties and reusability.

Innovation Solution

Incorporating identification means on the outside of the shaft adjacent to the wear indicators, such as recesses, elevations, or profiles, to unambiguously identify wear indicators and prevent misinterpretation of thread damage, ensuring reliable reusability assessment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wear indicator means are provided on the thread to show wear degree, then the ability to assess screw reusability is improved, but the risk of misinterpretation of thread damage as wear indicators increases

Engineering Contradiction:
Improvereusability assessment reliabilityVSAvoidmisinterpretation of thread damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary element - the identification means (such as markings, codes, or distinct features) that mediates between the wear indicator means and the user's assessment. This intermediary provides unambiguous identification that distinguishes intentional wear indicators from accidental thread damage, thereby resolving the misinterpretation problem while maintaining reliable reusability assessment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the identification system into distinct components: the wear indicator means (showing wear degree) and the identification means (providing unambiguous recognition). This segmentation allows each component to perform its specific function independently, preventing confusion between wear indicators and thread damage while enabling reliable assessment of screw reusability.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If multiple wear indicator means are provided on the thread, then the precision of wear assessment is improved, but the complexity of identifying genuine wear indicators versus thread damage increases

Engineering Contradiction:
Improvewear assessment precisionVSAvoididentification complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The identification means serves as an intermediary that simplifies the recognition process despite multiple wear indicators being present. By providing distinct identification features (such as specific markings or patterns) associated with each wear indicator, the system maintains measurement precision while reducing identification complexity for the user.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If wear indicator means are made visible on the thread, then the ease of assessing screw condition is improved, but the risk of accidental damage to the thread structure increases

Engineering Contradiction:
Improvecondition assessment easeVSAvoidthread structural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent applies local quality by making only specific portions of the thread structure visible or marked as wear indicators, rather than exposing the entire thread. The identification means are placed at specific locations that provide sufficient wear information while preserving the overall structural integrity and strength of the thread.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2273134B1Thread tapping screw
Publication Date: 2016.03.23 HILTI AG
  • EP2273134B1 patent drawingFigure 1~3

AI summary

A thread-forming screw (11) with a shank (12) having a first end (13) and an opposing second end (14) with a load-bearing element (15), and with a thread (16) extending at least partially along the length of the shank (12), wherein several wear indicator elements (18) are provided on the thread (16). Identification elements (21, 26) are provided on the screw (11) for identifying the wear indicator elements (18).