Hydraulic Expansion Chuck for Compact Drill Feed Tool Changes

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Solution Overview

Problem

Existing tool applications with limited space face challenges in easily and cost-effectively changing tools due to the need for permanently connected adapter pieces, which increase material costs and require constant reconnection, particularly in drill feed units like those used in aircraft construction.

Innovation Solution

A hydraulic expansion chuck with a clamping receptacle for releasable tool clamping and a design that allows for interchangeable use in confined spaces, featuring a maximum width of 5-40 mm, and a mechanism using pressurized fluid to securely clamp and release tools, combined with a centering surface for stable connection to a drill feed unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adapter pieces are permanently shrunk onto the drill, then the drill can be connected to the drill feed unit, but material costs increase and the adapter pieces must be disposed of along with the worn drill

Engineering Contradiction:
Improveconnection stabilityVSAvoidmaterial waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent introduces a reusable intermediate piece (adapter) that remains on the drill feed unit while allowing different drills to be attached and detached. This intermediary component enables multiple drills to use the same adapter, eliminating the need to permanently shrink adapters onto each drill and thus preventing material waste when drills are replaced.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If adapter pieces are permanently connected to the drill, then the drill can be securely attached to the drill feed unit, but additional parts and materials are required for each tool replacement

Engineering Contradiction:
Improveattachment securityVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The adapter piece is designed with universal functionality to work with multiple different drill bits. Instead of having a dedicated adapter for each drill (increasing part complexity), a single reusable adapter serves multiple drills, reducing the total number of parts and materials needed while maintaining secure attachment through its hydraulic expansion mechanism.

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

3Ease of operation

If a hydraulic expansion chuck is used in confined spaces, then tool clamping is enabled, but the chuck size must be very small (5-40 mm width)

Engineering Contradiction:
Improvetool clamping capabilityVSAvoidchuck size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent employs hydraulic expansion technology within a compact chuck design. Pressurized fluid causes the chuck jaws to expand radially outward to clamp the tool, allowing a small external dimension (5-40 mm width) to achieve sufficient clamping force. The hydraulic mechanism enables the chuck to generate large clamping forces from a compact size by using fluid pressure to actuate the expansion movement.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 simple, cost-effective, and material-saving drill bit replacement without disposing of adapter pieces, allowing for precise tool changes in limited spaces, such as drill feed units, by using a hydraulic expansion chuck with a centering surface for stable alignment.

Implementation Method 1

In a first functional position of the hydraulic expansion chuck, a first pressure value exists in the at least one pressure chamber, wherein an inner surface of the clamping wall is elastically deformed into the interior of the clamping space at the first pressure value

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

an inner surface of the clamping wall is elastically deformed into the interior of the clamping space

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the centering surface is arranged radially outwardly offset from the connecting piece... ensures that the longitudinal axis of the hydraulic chuck is aligned or coincides with the axial direction of the holder

Methodology Applied
Scientific EffectGeometric centering: Geometry

Data Source

PatentEP3670045B1Hydraulic expansion chuck and drill feed unit
Publication Date: 2025.10.01 MAPAL DR KRESS SE & CO KG
  • EP3670045B1 patent drawingFigure 1
  • EP3670045B1 patent drawingFigure 2
  • EP3670045B1 patent drawingFigure 3

AI summary

The invention relates to a hydraulic expansion chuck (200) with a clamping receptacle (225) for releasably clamping a tool, wherein the hydraulic expansion chuck (200) has a maximum width dimension of at least 5 mm to at most 40 mm, preferably at least 7 mm to at most 35 mm, preferably at least 10 mm to at most 30 mm, preferably at least 15 mm to at most 20 mm, perpendicular to a longitudinal axis (A') of the hydraulic expansion chuck (200).