Rotatable Cutting Tool Inclined Key Surfaces

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Solution Overview

Problem

Existing rotatable cutting tools face challenges with complex and time-consuming insertion processes due to tight tolerances between key surface formations, leading to edge loading and reduced torque transfer efficiency.

Innovation Solution

The cutting tool features inclined key surface formations that form a convex shape around the tool axis, allowing for easier sliding and surface contact during torque introduction, reducing the need for complex threading and minimizing edge loading by providing a beveled insertion path for the wrench, enabling lower tolerance requirements and increased torque transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If parallel flat contact surfaces are used for key surface formations, then manufacturing is simple, but insertion process becomes complex and time-consuming due to tight tolerances

Engineering Contradiction:
Improvesimplicity of key surface formationVSAvoidinsertion time
Core Design Contradiction:
Ease of manufactureVSLoss of time

Solution Approach 1:

The patent applies curvature by forming the key surface areas with a radius of curvature R1 that is smaller than the radius of curvature R2 of the adjacent key surface areas. This creates a convex shape that facilitates easier insertion by guiding the wrench onto the tool, thereby reducing insertion time while maintaining manufacturing simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If parallel flat contact surfaces are used for key surface formations, then manufacturing is simple, but edge loading occurs during torque introduction

Engineering Contradiction:
Improvesimplicity of key surface formationVSAvoidedge loading
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies curvature by forming the key surface areas with a radius of curvature R1 that is smaller than the radius of curvature R2 of the adjacent key surface areas. This creates a convex shape that facilitates easier insertion by guiding the wrench onto the tool, thereby reducing insertion time while maintaining manufacturing simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent applies local quality by creating different curvature radii at different locations on the key surface areas. The first key surface areas have a smaller radius of curvature R1, while the second key surface areas have a larger radius of curvature R2. This localized variation in curvature optimizes both insertion ease and torque distribution to prevent edge loading.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If tight tolerances are used between nominal jaw width and nominal distance of key surface formations, then precision is improved, but insertion process becomes lengthy and patience-requiring

Engineering Contradiction:
Improvetolerance between jaw width and key surface distanceVSAvoidthreading process time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies curvature by forming the key surface areas with a radius of curvature R1 that is smaller than the radius of curvature R2 of the adjacent key surface areas. This creates a convex shape that facilitates easier insertion by guiding the wrench onto the tool, thereby reducing insertion time while maintaining manufacturing simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Ease of manufacture

If parallel flat contact surfaces are used, then manufacturing is simple, but torque transfer efficiency is reduced due to edge loading

Engineering Contradiction:
Improvesimplicity of key surface formationVSAvoidtorque transfer efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies curvature by forming the key surface areas with a radius of curvature R1 that is smaller than the radius of curvature R2 of the adjacent key surface areas. This creates a convex shape that facilitates easier insertion by guiding the wrench onto the tool, thereby reducing insertion time while maintaining manufacturing simplicity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent applies local quality by creating different curvature radii at different locations on the key surface areas. The first key surface areas have a smaller radius of curvature R1, while the second key surface areas have a larger radius of curvature R2. This localized variation in curvature optimizes both insertion ease and torque distribution to prevent edge loading.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3124150B1Rotatable machining tool
Publication Date: 2020.09.02 FRANZ HAIMER MASCHINENBAU KG
  • EP3124150B1 patent drawingFigure 1
  • EP3124150B1 patent drawingFigure 2a~2b
  • EP3124150B1 patent drawingFigure 3

AI summary

A rotatable cutting tool (10), which extends along a tool axis (W) defining an axial direction, has in a first axial longitudinal end region (12) a cutting formation (13) which is designed for material removal from a workpiece, and has in a second axial longitudinal end region (18) opposite the first a screw connection formation (20) which is designed for screw connection with a coupling component (24), and wherein the cutting tool (10) has key engagement surface formations (30, 36) diametrically opposed to each other with respect to the tool axis (W), which are designed for torque-transmitting contact engagement with key surfaces of a key.According to the invention, each of the key attack surface formations (30, 36) has at least two key attack surface areas (32/34, 38/40) arranged circumferentially around the tool axis (W) at a distance from each other, which are inclined away from each other in such a way that they form a vertex (S) projecting away from the tool axis (W).