Dual-Thread Clamping Device for Tool-Less Loosening

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Solution Overview

Problem

Existing clamping devices for disc-shaped tools in machine tools, such as circular saws and angle grinders, face issues with self-tightening during operation and require large auxiliary tools for loosening, and existing solutions like planetary gears are expensive and complex.

Innovation Solution

A clamping device with a threaded connector featuring two threads of different pitches, where the base thread allows quick attachment and the additional thread with a lower pitch provides high contact pressure, and a return spring prevents over-tightening, enabling manual loosening without tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a single-threaded connector is used for quick attachment, then attachment speed is improved, but contact pressure is insufficient

Engineering Contradiction:
Improveattachment speedVSAvoidcontact pressure
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The thread is segmented into two distinct threads with different pitches: a base thread for quick attachment and an additional thread for high contact pressure. This segmentation allows each thread to optimize for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the threaded connector are given different local qualities through the two threads with different pitches. The base thread provides quick engagement while the additional thread provides fine-adjustment clamping force, creating localized functional differentiation.

Inventive Principle:
Principle #3Local quality

2Force

If a planetary gear mechanism is used to increase clamping force, then contact pressure is improved, but device complexity and cost increase

Engineering Contradiction:
Improveclamping forceVSAvoidmechanism complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The complex planetary gear mechanism is extracted and replaced with a simple dual-threaded connector. The essential function of generating high clamping force is achieved through the additional thread with low pitch, eliminating the need for complex gear systems.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive complex planetary gear mechanisms with a simple, inexpensive dual-threaded connector that achieves the same clamping force function through a more economical design.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Force

If a strong spring element is used to provide clamping force, then contact pressure is improved, but the clamping device becomes prone to self-tightening

Engineering Contradiction:
Improvecontact pressureVSAvoidself-tightening prevention
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The dual-threaded connector enables the clamping device to be self-adjusting. The additional thread allows the user to manually adjust the clamping force by rotating the handwheel, making the system self-serviceable and preventing self-tightening through user control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The clamping force is made dynamic and adjustable through the additional thread mechanism. Instead of a fixed spring force, the system allows dynamic adjustment of clamping pressure through manual rotation of the handwheel on the additional thread.

Inventive Principle:
Principle #15Dynamics

4Force

If the additional thread has a low pitch to increase contact pressure, then clamping force is improved, but loosening becomes difficult

Engineering Contradiction:
Improvecontact pressureVSAvoidloosening ease
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The loosening process uses periodic action through the return spring that alternates between maintaining clamping force and providing axial relief. The spring periodically releases the handwheel from the threaded connector, allowing easy manual loosening despite the low-pitch additional thread.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The return spring acts as an intermediary mechanism between the handwheel and threaded connector. It mediates the loosening process by providing axial relief that overcomes the frictional connection, making it easy to manually loosen the clamping device.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 ensures secure clamping and easy tool-free loosening of disc-shaped tools, preventing self-tightening and reducing the need for expensive complex mechanisms, making the process more efficient and cost-effective.

Implementation Method 1

a return spring (13) which pushes the handwheel (8) axially away from the threaded connector (5)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the frictional connection of the pressure flange (14) on the tool (1) can thus be overcome by hand

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2006058B1Clamping device for tool-less tightening
Publication Date: 2010.04.28 METABOWERKE
  • EP2006058B1 patent drawingFigure 1~2
  • EP2006058B1 patent drawingFigure 3~4
  • EP2006058B1 patent drawingFigure 5~6

AI summary

The device has a compression flange (14) exteriorly surrounding a connection-sided flange (7) of a threaded connection (5). The compression flange is arranged on a hand wheel (8) at a side turned toward the connection-sided flange of the threaded connection. The compression flange is axially adjustable by rotation of the wheel relative to the threaded connection. The flange (14) is axially pressed on a tool or a pressure disk attached to the tool for axially clamping the tool to a flange of a drive shaft.