Friction Cone Clamping with Retractable Centering for Precision Grinding

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Solution Overview

Problem

Friction cone clamping systems require reclamping after grinding the workpiece to accommodate it in the friction cone, limiting the ability to perform cylindrical grinding before mounting in the friction cone.

Innovation Solution

A friction cone clamping system with a rotationally symmetrical base body and a centering element that can be displaced between extended and retracted positions, allowing initial holding and clamping during cylindrical grinding, followed by pressing the workpiece into the friction cone after releasing the centering element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the workpiece is ground before mounting in the friction cone, then cylindrical grinding precision is improved, but reclamping is required which increases machining time and reduces productivity

Engineering Contradiction:
Improvecylindrical grinding precisionVSAvoidmachining time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent divides the centering function into two distinct components: a removable centering element for grinding operations and a fixed friction cone for final machining. This segmentation allows each component to be optimized for its specific function without compromising the other, enabling precision grinding followed by direct mounting in the friction cone without reclamping.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The centering element is extracted as a separate, removable component from the friction cone assembly. This extraction allows the workpiece to be initially centered and ground using the removable centering element, then transferred to the friction cone for final machining operations without requiring reclamping, thus resolving the contradiction between precision and productivity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If a removable centering element is added to enable grinding before mounting, then versatility is improved, but device complexity increases

Engineering Contradiction:
Improvegrinding capabilityVSAvoidsystem structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The friction cone assembly is designed to serve multiple functions: the removable centering element enables cylindrical grinding operations, while the fixed friction cone handles final precision machining. This multi-functionality allows a single device to perform both grinding and machining operations, improving versatility without requiring entirely separate systems.

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

Solution Approach 2:

The removable centering element is designed to nest within the friction cone assembly during grinding operations, then be removed and replaced with the workpiece for final machining. This nesting approach allows the centering function to be integrated into the friction cone system while maintaining the ability to switch between different operational modes, balancing versatility and complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Stability of the object's composition

If the friction cone is firmly connected to the spindle, then rigidity is improved, but the workpiece cannot be easily released after strong frictional engagement

Engineering Contradiction:
ImproverigidityVSAvoidworkpiece release
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The ejector mechanism serves as an intermediary device between the workpiece and the friction cone. It provides a controlled method to overcome the strong frictional engagement and release the workpiece without compromising the rigid connection between the friction cone and the spindle. This intermediary mechanism allows easy workpiece release while maintaining system rigidity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The ejector mechanism is pre-positioned and spring-loaded within the friction cone assembly, ready to actuate when needed. This preliminary preparation allows for quick and easy workpiece release by simply activating the ejector, which automatically applies the necessary force to overcome frictional engagement without requiring manual intervention or compromising the rigid spindle connection.

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

Enables precise cylindrical grinding without reclamping, ensuring high precision and efficient machining by transmitting spindle rotation to the workpiece through the centering element, and facilitating automated replacement of worn friction cone attachments.

Implementation Method 1

The frictional engagement created during the pressing process results in the rotation of the machine spindle being transferred to the workpiece

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a spring (22), in particular a compression spring, which acts on the centering element (130) in the axial direction

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

a pull/push rod (20), in particular an axially displaceable pull/push rod, which acts on the centering element (130) in the axial direction

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP4635657A1Friction cone tensioning system for a machine tool, machine tool and method for machining a workpiece with a machine tool
Publication Date: 2025.10.22 ADELBERT HAAS GMBH
  • EP4635657A1 patent drawingFigure 1
  • EP4635657A1 patent drawingFigure 2
  • EP4635657A1 patent drawingFigure 3

AI summary

Provided is a friction cone clamping system (100, 200) with a rotationally symmetrical base body (110, 210), on which a friction cone attachment (120, 220) with a workpiece holder (123, 223) forming a friction cone is arranged, and with a centering element (130, 230) with a centering tip (131, 231), wherein the centering element (130, 230) is arranged parallel to the axis of symmetry of the rotationally symmetrical base body (110, 210) displaceably in an opening passing through the base body (110, 210) and the friction cone attachment (120, 220) concentrically to the axis of symmetry of the rotationally symmetrical base body (110, 210), which opening merges into the workpiece holder (123, 223), so that the centering element (120, 230) can be moved between an extended position in which the centering tip (131, 231) protrudes from the workpiece holder (123, 223) and a retracted position in which the centering tip (131, 231) is located within the workpiece holder (123, 223),in which the base body (110, 210) has at least one clamping means (115, 215, 216) which is designed and configured to centrally clamp the centering element (130, 230) at least in the extended position, so that a rotation of the base body (110, 210) is transmitted to the centering element (130, 230), a machine tool with such a friction cone clamping system and a method for machining a workpiece with such a machine tool.