Aluminum-Alloy Hand Tool Structure for Lower Weight and Strength

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Hand-held tools such as sheet metal shears and seaming pliers used by roofers, plumbers, and ironworkers are heavy, posing a physical burden and safety risk due to their weight, which restricts movement and balance during work.

Innovation Solution

A hand-held tool with handle elements and jaw elements made of aluminum alloy, featuring a pivotable joint, reducing weight through a one-piece design and manufacturing processes like drop forging and laser welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If hand-held tools are made from steel materials to ensure function and strength, then the tools meet high demands on function and strength, but the tools have increased weight which restricts freedom of movement and poses safety risks

Engineering Contradiction:
Improvetool strengthVSAvoidtool weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials by combining aluminum alloy (for lightweight structure) with steel components (for cutting edges and high-stress areas). The handle elements and jaw elements are made of aluminum alloy to reduce weight, while steel inserts or coatings are used in regions requiring high strength and wear resistance, thus resolving the contradiction between overall weight reduction and localized strength requirements

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent implements local quality by applying different materials to different parts of the tool: aluminum alloy for the main body (low density, low weight), steel for cutting edges and joint components (high strength, high wear resistance). This allows each component to have the optimal material properties for its specific function, maintaining strength where needed while minimizing overall weight

Inventive Principle:
Principle #3Local quality

2Reliability

If hand-held tools are made from steel materials to ensure function, then the tools meet high demands on function, but the tools present potential danger and restrict freedom of movement in exposed positions

Engineering Contradiction:
Improvetool reliabilityVSAvoidfreedom of movement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The use of aluminum alloy as the primary material provides sufficient strength-to-weight ratio for reliable tool operation, while the reduced weight significantly improves ease of operation and safety in exposed positions. Steel components are strategically placed only where high strength is critical, maintaining reliability without compromising mobility

Inventive Principle:
Principle #40Composite materials

3Weight of moving object

If hand-held tools are made from aluminum alloy to reduce weight, then the tools offer reduced weight for improved handling and energy savings, but the tools may not meet high requirements and stresses encountered in use

Engineering Contradiction:
Improvetool weightVSAvoidtool strength
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent resolves this contradiction by creating a composite structure where aluminum alloy provides the lightweight framework and steel components (inserts, coatings, or reinforcements) provide the necessary strength and wear resistance. This combination achieves both weight reduction and sufficient strength to meet operational requirements

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by concentrating steel material only in high-stress regions such as cutting edges, jaw contact surfaces, and joint areas, while the majority of the tool body remains aluminum alloy. This localized reinforcement maintains overall strength requirements while maximizing weight reduction benefits

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 reduced weight enhances user-friendliness and safety by minimizing energy expenditure and maintaining functionality under demanding conditions.

Implementation Method 1

a joint, which joint forms the two handle elements pivotable relative to each other about a rotation axis

Methodology Applied
Scientific EffectMechanical rotation: Hinge

Implementation Method 2

a scissor blade is arranged on each jaw element of the sheet metal shears, preferably by welding, particularly preferably by laser welding

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Implementation Method 3

the two handle elements are manufactured by a forging process, preferably drop forging

Methodology Applied
Scientific EffectForging: Plasticity

Data Source

PatentEP4609991A1Hand-held tool and process for its manufacture
Publication Date: 2025.09.03 ING JOHANN HOERTNAGL WERKZEUGE GMBH
  • EP4609991A1 patent drawingFigure 1~4
  • EP4609991A1 patent drawingFigure 5~7
  • EP4609991A1 patent drawingFigure 8~10

AI summary

Hand-held tool, comprising: - two handle elements (3, 4), each formed in one piece with a jaw element (5, 6), and - a joint (7), which joint (7) connects the two handle elements (3, 4) so ​​as to be pivotable relative to one another about a rotation axis (8), wherein a gap between the two jaw elements (5, 6) can be changed by pivoting the handle elements (3, 4) relative to one another or the jaw elements (5, 6) can be placed against one another by the pivoting, wherein the two handle elements (3, 4) together with the respective jaw elements (5, 6) are made of an aluminum alloy.