Double-Conical Screwdriving Tool Holder for Precise Centering

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Solution Overview

Problem

Existing screw-in tools face challenges in achieving precise axial positioning and centering due to limitations in contact surface designs, such as radial collars and conical surfaces, which can lead to deformation and misalignment.

Innovation Solution

A screw-in tool with a support area formed by two conical contact surfaces of different cone angles, along with a tool holder featuring conical bearing surfaces, creates a double cone structure for enhanced centering and supporting, allowing for precise thread prestressing and reduced spreading forces, while additional spherical or cylindrical contact areas provide partial contact and independent preload.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conical contact surface is used to improve centering, then centering effect is improved, but outer walls of the tool holder deform outwards due to wedge effect

Engineering Contradiction:
Improvecentering precisionVSAvoidtool holder deformation
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The single conical contact surface is segmented into two conical contact surfaces with different cone angles. The first conical contact surface (with smaller cone angle) provides centering, while the second conical contact surface (with larger cone angle) provides support and balances radial forces, preventing tool holder deformation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the support area are given different geometric properties - the first conical contact surface has a smaller cone angle optimized for centering, while the second conical contact surface has a larger cone angle optimized for force distribution and preventing deformation. Each local region is optimized for its specific function.

Inventive Principle:
Principle #3Local quality

2Reliability

If conical surfaces with opposite pointing cones are used to balance radial forces, then tool interface protection is improved, but flexibility of the tool interface is reduced

Engineering Contradiction:
Improvetool interface protectionVSAvoidtool interface flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

Different local regions of the support area are assigned different cone angles optimized for specific functions. The first conical contact surface uses a smaller cone angle for centering, while the second uses a larger cone angle for force balancing. This localized optimization maintains flexibility while ensuring protection.

Inventive Principle:
Principle #3Local quality

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 configuration enables precise and reproducible positional accuracy of the screw-in tool, reduces elastic deformation, and increases the tool's service life by allowing for easier adjustment of thread preload and improved rigidity against radial loads.

Implementation Method 1

reduces elastic deformation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

improved centering and support

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2812142B1Screwdriving tool and tool holder for such a screwdriving tool
Publication Date: 2023.07.26 FRANZ HAIMER MASCHINENBAU KG
  • EP2812142B1 patent drawingFigure 1~5
  • EP2812142B1 patent drawingFigure 6~7
  • EP2812142B1 patent drawingFigure 8~9

AI summary

The invention relates to a screwdriving tool (1) and to a tool holder (2) for such a screwdriving tool. The screwdriving tool (1) contains a tool head (3) and a tool shank (4) having an outer thread (5) and a supporting region arranged between the tool head (3) and the outer thread (5). According to the invention, the supporting region is formed by two conical bearing faces (6, 8) having different cone angles.