Torque Calibration Device Using Flexible Element and Mechanical Stop

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Solution Overview

Problem

Existing calibration methods for force and torque measuring devices are expensive, require periodic removal for calibration, and do not account for dynamic measurement conditions, leading to linearity errors and inconvenience in production.

Innovation Solution

A calibration device without sensors, capable of dynamic calibration in both directions of movement or rotation, using flexible elements and stops to ensure linearity of torque/angle functions, allowing for instantaneous calibration of motorized and non-motorized devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are used for calibration, then measurement precision is improved, but device cost increases

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration device cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces expensive sensors with a simple mechanical stop that defines a fixed displacement limit. The stop is a low-cost mechanical component that physically prevents the movable part from exceeding a predetermined displacement, providing calibration without requiring costly sensing elements.

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

Solution Approach 2:

The calibration device uses its own mechanical structure (the stop) to define the calibration point without needing external measurement equipment. The system calibrates itself by using the predetermined displacement limit as the reference point, eliminating the need for separate measurement instruments.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If external calibration is performed, then measurement precision is improved, but productivity decreases due to device immobilization

Engineering Contradiction:
Improvecalibration accuracyVSAvoidproduction control continuity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The calibration device enables in-workshop calibration without requiring removal from the production environment. The device can be calibrated in place using the predetermined displacement stop, allowing calibration to be performed during production cycles without immobilizing the device or disrupting production control.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If static calibration using calibration weights is performed, then ease of operation is improved, but measurement precision deteriorates due to linearity errors

Engineering Contradiction:
Improvecalibration simplicityVSAvoidtorque/angle linearity
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transitions from static calibration (using fixed weights) to dynamic calibration by using a movable part that can be displaced to different positions. The movable part allows calibration at multiple torque/angle points along the measurement range, enabling verification and correction of linearity errors through dynamic movement rather than static positioning.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device is pre-calibrated at the factory to establish the relationship between movable part displacement and applied torque. This preliminary calibration creates a predictable, repeatable system where the stop defines a known displacement corresponding to a specific torque value, allowing field calibration without complex procedures.

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If the device is removed for calibration, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The calibration device enables in-workshop calibration without requiring removal from the production environment. The device can be calibrated in place using the predetermined displacement stop, allowing calibration to be performed during production cycles without immobilizing the device or disrupting production control.

Inventive Principle:
Principle #25Self-service

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 cost-effective, simple, and efficient calibration method that ensures accurate dynamic calibration, reducing production downtime and linearity errors, and is compatible with various measuring equipment.

Implementation Method 1

The two parts 2 and 3 are connected by one or more flexible elements 4 forming blades or profiles of variable cross-section

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A torque or force calibration device... comprises a fixed part 3 and a movable part 2... The angular displacement or translational displacement of the moving part 2 is limited by a stop 7

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3460437B1Dynamic torque and/or force calibration device
Publication Date: 2021.10.27 ETA SA MFG HORLOGERE SUISSE
  • EP3460437B1 patent drawingFigure 1~2
  • EP3460437B1 patent drawingFigure 3~6
  • EP3460437B1 patent drawingFigure 7~8b

AI summary

The present invention relates to a torque or force calibration device (1) for an apparatus (9) intended to measure or apply torque or force respectively, said device (1) comprising a first part (3), a second part (2) and at least one flexible element (4) connecting the first part (3) to the second part (2), the second part (2) being mounted movable in rotation or translation relative to the first fixed part (3), the device (1) comprising a stop (7) which limits the movement of the second part (2) and thereby fixes the maximum torque or maximum force of the calibration device (1).