Wedge Chuck Assembly for Fast, Secure Workpiece Holder Clamping

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Solution Overview

Problem

Conventional machine tools with multi-axis workpiece arms face challenges in achieving compact dimensions, secure clamping, and quick clamping/release mechanisms for workpiece holders.

Innovation Solution

A multi-axis workpiece arm with a chuck and a displaceable clamping element, featuring a wedge-shaped geometry, allows for variable clamping force application and release by moving the clamping element relative to the chuck, utilizing a disk spring for secure clamping and compressed air for controlled release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional chuck with multiple clamping jaws and a screw mechanism is used, then the workpiece holder can be clamped securely, but the clamping and releasing process becomes time-consuming and the structure becomes complex

Engineering Contradiction:
Improvesecure clampingVSAvoidclamping and releasing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the essential clamping function from the complex multi-jaw screw mechanism and implements it through a single displaceable clamping element that acts directly on the workpiece holder. This simplifies the mechanism while maintaining secure clamping through direct contact and leverages the wedge-shaped geometry for force multiplication.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a screw mechanism that pushes jaws into a cone (conventional approach), the patent inverts the approach by using a displaceable clamping element with wedge-shaped surfaces that directly clamp the workpiece holder through relative displacement. This reversal enables quicker operation while maintaining reliability.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If a conventional chuck with multiple clamping jaws is used, then the workpiece holder can be clamped securely, but the device dimensions increase and complexity increases

Engineering Contradiction:
Improvesecure clampingVSAvoidchuck structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential clamping function from the complex multi-jaw screw mechanism and implements it through a single displaceable clamping element that acts directly on the workpiece holder. This simplifies the mechanism while maintaining secure clamping through direct contact and leverages the wedge-shaped geometry for force multiplication.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of multiple clamping jaws into a single displaceable clamping element. The wedge-shaped geometry of this element combines force application and clamping action in one component, reducing the number of parts and simplifying the overall chuck structure.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If a compact chuck design is used, then the machine tool dimensions are reduced, but the clamping force application becomes difficult

Engineering Contradiction:
Improvechuck volumeVSAvoidclamping force
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The patent introduces compressed air as a power source to actuate the displaceable clamping element. The compressed air provides the necessary force to overcome spring pressure and displacement the clamping element, enabling compact design while maintaining sufficient clamping force through pneumatic actuation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical state and properties by using compressed air (gas under pressure) to generate the clamping force. This allows for compact dimensions while achieving high clamping forces through the controlled introduction of pneumatic pressure to displace the clamping element against the spring force.

Inventive Principle:
Principle #35Parameter changes

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 a compact, secure, and efficient clamping and releasing mechanism for workpiece holders, ensuring reliable clamping and easy operation with precise control.

Implementation Method 1

the chuck (120) and the clamping element (109) have such a geometry, in particular wedge-shaped in cross section at least in sections, that the clamping element (109) is designed to apply a clamping force to the workpiece holder (111) when it is displaced relative to the chuck (120)

Methodology Applied
Scientific EffectWedge: Wedge

Implementation Method 2

utilizing a disk spring for secure clamping

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 3

and compressed air for controlled release

Methodology Applied
Scientific EffectCompressed air: Pressurisation

Data Source

PatentEP3345703B1Assembly of machine tool and tension holder of a workpiece and chuck for same
Publication Date: 2021.04.07 HUBER MARTIN
  • EP3345703B1 patent drawingFigure 1

AI summary

The invention relates to an arrangement comprising a machine tool (10) and a workpiece holder (111) connected to a workpiece (14), wherein the workpiece holder (111) has at least one radially outwardly extending surface (111a), in particular a substantially planar surface, which is designed for contact with a clamping element (109) of a multi-axis workpiece arm (11) arranged radially between the workpiece holder (111) and a chuck (120), wherein the clamping element (109) is displaceable relative to the chuck (120) for clamping and releasing the workpiece holder (111), and wherein the clamping element (109) is designed to vary a clamping force (F) applied to the workpiece holder (111) when displaced relative to the chuck (120).