Chisel Shank Structured Section Prevents Jamming

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Solution Overview

Problem

Hand-held power chiseling tools often get stuck in rock, particularly when chiseling cement-containing rock, due to the lack of effective measures to prevent jamming during operation.

Innovation Solution

A chisel tool with a structured section on the shank featuring inclined ribs and channels, which creates additional space through vibration, reducing the risk of sticking by allowing for better dust removal and reduced friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the chisel tool is used with powerful hand tools for chiseling rock, then the chiseling power and efficiency are improved, but the risk of the tool becoming stuck in the rock increases

Engineering Contradiction:
Improvechiseling powerVSAvoidrisk of tool jamming
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent utilizes the vibration typically occurring during operation of the chisel tool to create additional clearance along the tool shank within the chisel hole. The structured section with inclined ribs interacts with the rock walls through vibration, preventing the tool from becoming stuck while maintaining high chiseling power.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The tool shank is given a localized structured section with inclined ribs at a specific position, rather than modifying the entire shank. This structured section has different geometric properties (inclined ribs at 45-60 degrees) compared to the rest of the smooth shank, creating local clearance zones that prevent jamming without affecting overall tool strength.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the tool shank has a structured section with inclined ribs, then the clearance and dust removal are improved, but the device complexity increases

Engineering Contradiction:
Improvedust removal efficiencyVSAvoidstructured section geometry
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The structured section is divided into multiple inclined ribs that are spaced apart, creating individual clearance channels between adjacent ribs. This segmentation allows chisel dust to be effectively removed through the spaces between ribs while maintaining a relatively simple overall structure that can be manufactured using conventional processes.

Inventive Principle:
Principle #1Segmentation

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 structured section effectively prevents the chisel tool from getting stuck in rock holes by creating space through vibration and improved dust removal, enhancing operational efficiency and reducing jamming risks.

Implementation Method 1

the structured section, due to the vibration typically occurring during operation of the chisel tool, can contribute to creating additional clearance along the tool shank

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

The outer edge of the rib can be particularly easily configured for grinding and/or sawing. The outer edge may be sharpened and/or hardened.

Methodology Applied
Scientific EffectGrinding: Abrasion

Implementation Method 3

The structured section can be configured for rubbing and/or sawing to further enhance its clearance-creating effect in conjunction with the vibration.

Methodology Applied
Scientific EffectSawing: Abrasion

Data Source

PatentEP3928928B1Chiseling tool with structured section
Publication Date: 2024.12.04 HILTI AG
  • EP3928928B1 patent drawingFigure 1
  • EP3928928B1 patent drawingFigure 2

AI summary

The invention relates to a chisel tool (10), in particular for a hand-held power tool, comprising a tool tip (12) having at least one wedge-shaped surface (16) and a tool shank (14). It is characterized in that the tool shank (14) has a structured section (18) on its circumference. The invention reduces the risk of the chisel tool becoming stuck during chiseling.