Knife Sharpening Carriage With Constant Force Edge Control

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Solution Overview

Problem

Existing knife sharpeners require user input for force and angle, leading to inconsistent sharpening and potential damage, and often expose users to the blade, increasing injury risk.

Innovation Solution

A knife sharpener device with a spring-biased sharpening element and clamping assembly that provides a constant force and maintains the knife in a fixed position, using a carriage assembly to move the sharpening element along a guide track, ensuring consistent and safe sharpening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional manual sharpening methods are used, then flexibility and control over sharpening process is maintained, but sharpening consistency and efficiency deteriorate

Engineering Contradiction:
Improvesharpening efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The sharpening system is divided into separate functional modules: a holder assembly for securing the knife, a sharpening element assembly with abrasive media, and a positioning mechanism. This segmentation allows each component to be optimized independently while maintaining overall system simplicity and effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system incorporates self-aligning features where the knife blade automatically positions itself relative to the sharpening element through mechanical guidance. The holder assembly and positioning mechanism work together to ensure consistent blade orientation without requiring complex external alignment procedures, thereby improving sharpening consistency while keeping the device relatively simple.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If sharpening parameters are not standardized, then adaptability to different knife types is maintained, but sharpening consistency deteriorates

Engineering Contradiction:
Improvesharpening consistencyVSAvoidknife type adaptability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The holder assembly is designed with universal mounting features that can accommodate various knife types and sizes. The positioning mechanism provides standardized reference points that work across different blade configurations, enabling consistent sharpening parameters to be applied universally while maintaining adaptability to different knife types through adjustable holder positions.

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

3Manufacturing precision

If sharpening process is not controlled, then operational simplicity is maintained, but sharpening quality deteriorates

Engineering Contradiction:
Improvesharpening qualityVSAvoidoperational simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The system pre-positions the knife blade relative to the sharpening element through the holder assembly and positioning mechanism before sharpening begins. This preliminary positioning ensures that the blade is correctly aligned and secured, eliminating the need for complex real-time control during the sharpening process itself. Users simply need to place the knife in the holder and activate the sharpening element, maintaining operational simplicity while ensuring consistent sharpening quality.

Inventive Principle:
Principle #10Preliminary action

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 achieves reproducible and controlled sharpening strokes, protecting users from the blade and preventing damage, while being user-friendly and accessible.

Implementation Method 1

a sharpening element, such as an abrasive element

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 2

The holder assembly may be moved along a guide rail or other guiding structure during the sharpening process

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4304811B1Knife sharpening device and method
Publication Date: 2026.05.06 SHARKNINJA OPERATING LLC
  • EP4304811B1 patent drawingFigure 1~2
  • EP4304811B1 patent drawingFigure 3
  • EP4304811B1 patent drawingFigure 4~5

AI summary

Knife sharpener systems and methods are provided. In one exemplary embodiment, a knife sharpening system can include a support structure configured to hold a knife having a handle and a blade extending therefrom, and a carriage assembly mounted on the support structure. The carriage assembly can have a sharpening element that is configured to sharpen a cutting edge of the blade. The carriage assembly can be movable relative to the knife blade to cause the sharpening element to apply a force to the cutting edge of the knife blade.