Blade Sharpening Device With Retaining Points

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Solution Overview

Problem

Existing knife sharpening devices require multiple fastening means, can exert excessive force on blades, leading to material scraping, damage, and contamination issues, and are not user-friendly, with complex assemblies and high manufacturing costs. They also fail to accommodate different types and qualities of knives effectively and pose safety risks due to exposed springs and sharpening inserts.

Innovation Solution

A knife sharpening device with a simplified design featuring a plate with a slot and two sharpening rods held at a predetermined angle by springs, where the rods pivot to accommodate blades of varying types, with a reduced number of components to minimize assembly complexity and safety hazards, and a modular design for easy maintenance and use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional knife sharpeners use multiple fasteners and complex assembly to secure sharpening rods, then the sharpening rods can be firmly fixed, but the device complexity increases and manufacturing costs rise

Engineering Contradiction:
Improvefixation of sharpening rodsVSAvoidnumber of fasteners and components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple fastening functions into a single integrated plate structure that secures both sharpening rods simultaneously. The plate with slot and retaining points eliminates the need for separate fasteners, reducing component count while maintaining reliable fixation of the sharpening rods during operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plate serves multiple functions: it supports the sharpening rods, provides structural framework, guides blade insertion through the slot, and secures rods with integrated retaining points. This multi-functional design replaces what would traditionally require multiple specialized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Force

If excessive restoring force is exerted by springs on the knife blade during sharpening, then the sharpening rods can be pushed apart effectively, but the blade may be damaged or material scraped off

Engineering Contradiction:
Improverestoring force of springsVSAvoiddamage to knife blade
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The plate features a specifically designed slot with controlled geometry and friction characteristics. This local structural quality allows the slot to grip the blade gently during insertion while the springs provide restoring force, preventing excessive force transmission to the blade that could cause damage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The plate and slot act as an intermediary between the springs and the knife blade. The slot guides and controls the interaction, allowing the springs to exert restoring force on the sharpening rods while the plate structure modulates this force to prevent direct excessive force application to the delicate blade edge.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the knife blade is tilted during insertion into the plate, then insertion may be easier for misaligned blades, but material will be scraped off the plate and blade damage can occur

Engineering Contradiction:
Improveinsertion of knife bladeVSAvoidscraping and damage during insertion
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The slot in the plate has specific geometric characteristics including tapered sections and controlled surface friction. These local quality features guide the blade into proper alignment during insertion, allowing easy entry while preventing tilting that would cause scraping or damage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The slot geometry is designed to preliminarily align the blade during insertion before the blade reaches the sharpening rods. The tapered and guided sections of the slot pre-position the blade correctly, preventing misalignment issues during the sharpening process.

Inventive Principle:
Principle #10Preliminary action

4Ease of operation

If sharpening inserts and springs are exposed and in the sphere of influence of user's hands, then assembly and maintenance may be simpler, but the risk of injury to the user's hands increases

Engineering Contradiction:
Improveassembly and maintenanceVSAvoidinjury risk to user
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The sharpening rods with exposed inserts and springs are nested within the protective enclosure formed by the plate and housing. This nesting provides physical protection against accidental contact while maintaining accessibility for intended operations.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The plate and housing structure act as a protective shell that encloses dangerous components. This thin-walled enclosure provides effective protection against finger injuries while allowing necessary operations through openings and access points.

Inventive Principle:
Principle #30Flexible shells and thin films

5Reliability

If a multitude of individual parts are used in the knife sharpener, then assembly and replacement require considerable technical expertise, but the manufacturing, repair and maintenance costs increase

Engineering Contradiction:
Improvefunctionality of knife sharpenerVSAvoidassembly and maintenance complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple individual components (fasteners, support structures, guides) are merged into the integrated plate assembly. This reduces the total number of parts requiring assembly and maintenance while maintaining all necessary functions for secure and reliable operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plate performs multiple functions simultaneously: structural support, rod fixation, blade guidance, and safety enclosure. This multi-functionality eliminates the need for separate specialized components, simplifying assembly and reducing manufacturing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 device ensures safe and effective sharpening of various knife types without damaging the blade or device, reduces manufacturing costs, and allows for easy cleaning and maintenance, while protecting users from injury and contamination.

Implementation Method 1

The two sharpening rods are held at a predetermined angle to one another by the action of springs

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3746266B1Blade sharpening device comprising retaining points
Publication Date: 2024.09.18 STALLEGGER HARALD
  • EP3746266B1 patent drawingFigure 1
  • EP3746266B1 patent drawingFigure 2
  • EP3746266B1 patent drawingFigure 3

AI summary

A blade sharpening device comprising: - a plate (1) comprising two sharpening rods (24; 25) which are pivotally mounted on the plate (1); The plate (1) has a slot (8) that is open at one end (7) and closed at the opposite end (6); The positioning of the sharpening rods (24; 25) and the slot (6) is axially flush relative to one another and allows a blade to be inserted; The sharpening rods (24; 25) each have at least one sharpening insert (30); In an idle position (19), the sharpening rods (24; 25) are held at a predefined distance from one other by the force of respective springs (29). In a sharpening position, as the blade is introduced, the sharpening rods (24; 25) can be spread apart against the force of the springs (29) when the blade makes contact with the sharpening inserts (30). The plate (1) has at least one point (42, 43, 44), at which the at least one sharpening rod (24; 25) is retained relative to the plate (1).