Clamping Device Spring Unit Segmentation

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Solution Overview

Problem

Existing clamping devices in machine tools utilize disk spring assemblies that are heavy, have limited service life, and are difficult to assemble, due to their large mass and high load requirements.

Innovation Solution

A compact clamping device with a spring unit comprising flexible spring elements between secured spring receptacles, allowing for easy assembly and disassembly, and adjustable spring properties through multiple units, secured against twisting and rotation, with a hydraulic, pneumatic, or electric release unit for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If disk spring assemblies are used to generate clamping force, then the required clamping force is achieved, but the mass becomes large and assembly effort increases

Engineering Contradiction:
Improveclamping forceVSAvoidmass of spring arrangement
Core Design Contradiction:
ForceVSWeight of moving object

Solution Approach 1:

The spring arrangement is divided into multiple individual spring elements (e.g., six bar-shaped elements) arranged circumferentially around the pull rod, replacing the monolithic disk spring assembly. This segmentation reduces the overall mass while maintaining the required clamping force through distributed elastic deformation of multiple elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spring elements can be made from composite materials combining high-strength metals or fiber-reinforced polymers, achieving the necessary mechanical properties with reduced mass compared to traditional disk springs. The bar-shaped elements utilize material properties to optimize the strength-to-weight ratio.

Inventive Principle:
Principle #40Composite materials

2Force

If disk spring assemblies are used to generate clamping force, then the required clamping force is achieved, but the assembly effort and complexity increase

Engineering Contradiction:
Improveclamping forceVSAvoidassembly effort
Core Design Contradiction:
ForceVSEase of manufacture

Solution Approach 1:

The spring arrangement consists of multiple independent bar-shaped spring elements that can be individually manufactured and then assembled around the pull rod. This modular segmentation allows for simplified manufacturing processes and easier assembly compared to the complex nested structure of disk springs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bar-shaped spring elements serve multiple functions: they provide elastic clamping force, can be arranged in various configurations to accommodate different tool sizes, and allow for easy replacement or adjustment. This multi-functionality reduces the need for multiple specialized components.

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

3Force

If disk spring assemblies are used, then high load capacity is achieved, but the service life becomes limited

Engineering Contradiction:
Improveload capacityVSAvoidservice life
Core Design Contradiction:
ForceVSDuration of action of stationary object

Solution Approach 1:

The bar-shaped spring elements are designed to flex dynamically during clamping and release cycles, distributing stress more evenly across the structure. This dynamic deformation pattern reduces stress concentration and fatigue accumulation compared to the rigid disk spring assembly, extending service life.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Using composite materials for the spring elements provides superior fatigue resistance and durability. The combination of high-strength metals or fiber-reinforced polymers maintains load capacity while withstanding repeated cycling better than traditional disk spring materials.

Inventive Principle:
Principle #40Composite materials

4Adaptability or versatility

If multiple spring units are arranged in a row, then the desired spring properties can be adjusted, but the complexity of securing against rotation increases

Engineering Contradiction:
Improveadjustability of spring propertiesVSAvoidsecuring against rotation
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The bar-shaped spring elements have asymmetric cross-sections or mounting configurations that naturally prevent rotation when installed. This asymmetric design provides inherent anti-rotation features without requiring additional complex securing mechanisms, while still allowing for adjustable spring properties through varying the number and arrangement of elements.

Inventive Principle:
Principle #4Asymmetry

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

The solution provides a lightweight, easily assembled, and adaptable clamping system with extended service life, reducing assembly effort and maintaining high performance through adjustable spring properties and efficient release mechanisms.

Implementation Method 1

a spring unit with a plurality of flexible spring elements arranged between a first and second spring receptacle

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the first spring receptacle contains a securing element designed, for example, as a securing pin. The securing element arranged on the first spring seat can, for example, positively engage in the tie rod or in a contact element arranged on the tie rod and secured against rotation

Methodology Applied
Scientific EffectMechanical Fastening: Mechanical Fastener

Data Source

PatentEP3165309B1Clamping device
Publication Date: 2018.06.20 OTT JAKOB & SPANNTECHN
  • EP3165309B1 patent drawingFigure 1
  • EP3165309B1 patent drawingFigure 2~3
  • EP3165309B1 patent drawingFigure 4~8

AI summary

The invention relates to a clamping device (1) for clamping a workpiece or a tool or tool holder (3) on a machine part (2) of a machine tool, comprising an axially (4) displaceable clamping rod (7), a clamping assembly (11) movable via the clamping rod (7) between a clamping position and a release position, a spring assembly (17) associated with the clamping rod (7) for generating the clamping or retraction force of the clamping assembly (11), and a release unit (25) by which the clamping assembly (11) can be moved via the clamping rod (7) against the force of the spring assembly (17) into the release position. The spring assembly (17) comprises at least one spring unit (18) with several flexible spring elements (29) arranged between a first and second spring receptacle (27, 28), wherein the first and second spring receptacles (27, 28) are secured against rotation relative to the clamping rod (7).