Lever-Lock Cutting Insert Clamping for Higher Holding Force

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Solution Overview

Problem

Conventional indexable cutting tools face issues with insufficient clamping force, particularly when using a lever-based system, and require separate cutting inserts for lever and screw-based systems, leading to increased management costs and inefficiencies.

Innovation Solution

The indexable cutting tool design features a lever with a defined fulcrum and pressing point configuration that allows for efficient force transmission to the cutting insert, using a screw to incline the lever and apply force close to its end, enhancing clamping force and adaptability to both lever and screw-based systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional L-shaped lever is used for clamping the cutting insert, then the cutting insert can be easily replaced, but the lever deforms under high cutting resistance leading to insufficient clamping force

Engineering Contradiction:
Improveease of replacementVSAvoidclamping force
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent changes the geometric parameters of the lever, specifically the distance between the fulcrum and the pressing point, to optimize the lever ratio. This allows the lever to generate sufficient clamping force without deforming under high cutting resistance, while maintaining ease of replacement operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a new dimension to the lever design by adding a pressing point on the lever body that is positioned at an optimized distance from the fulcrum. This creates an additional force application point that enhances the clamping force generation capability while preserving the lever's ease of operation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If different cutting inserts are prepared for lever-based and screw-based systems, then each system can be optimized for its specific clamping mechanism, but management costs increase due to having multiple insert types

Engineering Contradiction:
Improvesystem optimizationVSAvoidmanagement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the cutting insert with a universal through-hole structure that can accommodate both lever-based and screw-based clamping mechanisms. The through-hole is positioned and dimensioned such that it works effectively with either clamping system, allowing a single insert design to serve multiple functions and reducing management 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

This design achieves a greater clamping force and reduces the likelihood of lever deformation, allowing for reliable clamping of cutting inserts with acute corners and enabling the same cutting insert to be used for both lever and screw-based systems, thereby reducing management costs and improving processing stability.

Implementation Method 1

the lever (3) is inclined around the fulcrum on the lever (3) in a manner that the one end (31) which applies a clamping force moves forward in a pressing direction

Methodology Applied
Scientific EffectLever principle: Lever

Implementation Method 2

a screw (4) that presses the lever (3) to be inclined

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP2786821B1Replaceable-blade-edge cutting tool and cutting insert
Publication Date: 2022.08.17 TUNGALOY CORP
  • EP2786821B1 patent drawingFigure 1
  • EP2786821B1 patent drawingFigure 2
  • EP2786821B1 patent drawingFigure 3A~3B

AI summary

Provided is an indexable cutting tool of a lever-lock type applying a greater clamping force than conventional cutting tools. At a bottom of an insert fixing portion (11), there is formed a pillar-shaped lever (3) in a state in which one end (31) protrudes from a placement surface (12) of the insert fixing portion (11). A screw (4) applies a pressing force to the lever (3) between the one end (31) and a portion (32b3) such that the lever (3) is pressed and inclined with the portion (32b3) as a fulcrum in the middle of the lever (3) so that the one end (31) applies a clamping force to the cutting insert (2) .