Interchangeable Striking Head Wear Indicator

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Solution Overview

Problem

Existing striking tools with interchangeable heads suffer from limited lifespan due to premature wear, requiring frequent replacements and lacking effective anti-splinter safety features.

Innovation Solution

A tool with a striking head made of anti-splinter material softer than steel, featuring a frustoconical end piece and an annular metal ring acting as both a hoop and wear indicator, ensuring the buffer piece is compressed between the ring and the end piece, enhancing durability and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If a hard steel striking head is used, then durability is improved, but splinter generation increases and safety decreases

Engineering Contradiction:
ImprovedurabilityVSAvoidsplinter generation
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The striking head combines a hard steel body with a softer anti-splinter buffer piece (plastic, aluminum, or wood) that interfaces with the workpiece. This composite structure allows the steel to provide durability and structural integrity while the softer buffer material prevents splinter generation, resolving the contradiction between durability and safety.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If buffer material is made softer to reduce splinters, then safety is improved, but wear resistance decreases and lifespan shortens

Engineering Contradiction:
Improvesplinter generationVSAvoidlifespan
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The striking head is divided into two functional segments: a hard steel body that provides structural support and durability, and a separate replaceable buffer piece made of softer anti-splinter material. When the buffer piece wears out, only this segment needs replacement rather than the entire tool, thus maintaining safety while extending overall tool lifespan.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The buffer piece is designed with specific material parameters (hardness, density) that are softer than steel but optimized for wear resistance. The axial length of the buffer piece is also parameterized to ensure adequate material remains after wear, with the metal ring providing a visual indicator of when replacement is needed.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the metal ring covers the entire buffer piece, then wear indication is improved, but the buffer piece cannot be properly compressed between the ring and end piece

Engineering Contradiction:
Improvewear indicationVSAvoidcompression force distribution
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The metal ring is positioned to cover only a portion (at least 60%) of the axial length of the buffer piece, not the entire length. This local coverage provides sufficient wear indication while leaving space at the ends for proper compression of the buffer piece between the ring and the frustoconical end piece, ensuring optimal strength and shock absorption.

Inventive Principle:
Principle #3Local quality

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 solution extends the lifespan of striking tools by effectively distributing impact forces and providing anti-splinter protection, reducing wear and the need for frequent replacements while maintaining safety.

Implementation Method 1

a striking head formed by an interchangeable buffer piece (17), made of an anti-splinter material, having a hardness and a density lower than those of the steel of the body (11), and designed to dampen the mechanical shock

Methodology Applied
Scientific EffectShock absorption: Damping

Implementation Method 2

The buffer piece is compressed between the ring and the end piece, enhancing durability and safety

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2140990B1Tool with an interchangeable striking head
Publication Date: 2012.08.08 FISKARS FRANCE
  • EP2140990B1 patent drawingFigure 1~2
  • EP2140990B1 patent drawingFigure 3~4
  • EP2140990B1 patent drawingFigure 5~6

AI summary

The wedge has a steel body (11) comprising a rectilinear cutting edge and an impact head (13) at opposite end. The head is made of material with hardness less than that of steel. The head is formed by an interchangeable plastic tampon piece (17) connected on a truncated conical end piece (14) projecting from the body. The tampon piece is exteriorly surrounded by a metallic annular ring (15) that serves as a strap and wear indicator. The ring is housed under a shoulder (16) of the head and includes an axial length less than that of the head.