Knife Blade Hard-Edge Deposition Using Arc Welding

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Solution Overview

Problem

The existing method of manufacturing knife blades using laser deposition is inefficient due to the challenges of accurately and efficiently depositing harder materials onto the edge, often resulting in excess material usage and slow processing times.

Innovation Solution

The method involves using arc welding to precisely deposit a harder material in the form of a welding rod or metal cored rod onto the blade preform, allowing for exact placement and amount control, with the option of using a shielding gas to isolate the welding area and improve the weld quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser deposition is used to deposit the second material onto the blade preform, then the knife edge can be made hard and durable, but the process is slow and requires special attention to control powder amounts

Engineering Contradiction:
Improvedurability of knife edgeVSAvoidprocessing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces the laser-based powder deposition system with a conventional arc welding system using wire or rod feed. This substitution changes the fundamental mechanism from optical/thermal laser processing to electrical arc welding, enabling faster material deposition while maintaining control over material placement through automated wire feeding mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the deposition parameters by switching from powder form to wire/rod form of the second material. This parameter change allows for more consistent and controllable material feed rates, improving both the speed and reliability of the deposition process while eliminating the need for special powder handling precautions.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If laser deposition with powder is used, then the second material can be deposited onto the blade edge, but excess powder is used and precise control of material amount is difficult

Engineering Contradiction:
Improveprecision of material placementVSAvoidmaterial waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent changes the physical state and form of the second material from loose powder to structured wire or rod form. This parameter change enables precise control of material deposition through automated wire feeding systems, ensuring that exactly the required amount of material is deposited without excess powder usage or material waste.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the powder delivery and deposition system with a wire/rod feeding system driven by controlled mechanisms. This substitution provides more accurate and consistent material feed rate control, eliminating the difficulties associated with powder amount control and reducing material waste through precise deposition.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This approach enables the production of knife blades with a hard edge by ensuring accurate and efficient deposition of the second material, enhancing the durability and sharpness of the blade while reducing processing time and material waste.

Implementation Method 1

The deposition is in Figure 1 carried out by creating an arc 6 between the blade preform 1 and the arc welding tool 4. More precisely, in Figure 1 the electric arc is created between the blade preform 3 and the rod 7 which is fed through the arc welding tool 4.

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 2

Due to the electric power provided by the power source, an end of the rod melts and second material 5 from the rod is deposited on the edge 3 of the blade preform 1 by means of the electric arc.

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

The gas 11 is fed from an orifice 12 of the arc welding tool 4 towards the blade preform 1 to isolate the location 13 of the blade preform where arc welding is implemented from surroundings by the shielding gas 11.

Methodology Applied
Scientific EffectShielding gas isolation:

Data Source

PatentEP4190486A1Method of manufacturing a knife blade and knife blade
Publication Date: 2023.06.07 FISKARS FINLAND OY AB
  • EP4190486A1 patent drawingFigure 1~3
  • EP4190486A1 patent drawingFigure 4(A)~4(F)
  • EP4190486A1 patent drawing

AI summary

The invention relates to a of manufacturing a knife blade and to a knife blade. In the method, a blade preform (1) of a first material (2) is prepared. A second material (5) which is harder than the first material (2) is deposited on an edge (3) of the blade preform (1) by arc welding. The deposited second material (5) is sharpened to prepare a knife blade with a sharp edge.