Web-Tension Measuring Device with Bidirectional Force Sensing

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Solution Overview

Problem

Existing web tension measuring devices require complex designs with pre-tensioning elements to measure compressive forces and are limited by installation orientation, making reliable tension measurement challenging and inefficient.

Innovation Solution

A force sensor capable of detecting both tensile and compressive loads is integrated into a web tension measuring device, allowing for reliable tension measurement regardless of installation position, using a shear sensor to measure loads indirectly via reaction forces and moments on a roller's bearing arrangement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a compressive force sensor is used in a rocker-like structure with pre-tensioning elements, then compressive force measurement is enabled, but the device complexity increases and installation orientation is restricted

Engineering Contradiction:
Improvecompressive force measurement capabilityVSAvoiddesign complexity with pre-tensioning elements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the fundamental parameter of the force sensor from compressive-only to bidirectional (tensile and compressive) capability. This allows the same sensor to measure both types of forces without requiring complex pre-tensioning mechanisms or orientation restrictions, thereby reducing device complexity while maintaining measurement precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The force sensor is designed to perform multiple functions: measuring both tensile and compressive forces with a single device. This multi-functionality eliminates the need for separate sensors or complex mechanical arrangements for different measurement modes, directly reducing device complexity and removing installation orientation constraints.

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

2Reliability

If load cell orientation is fixed to measure compressive force, then measurement reliability is improved, but adaptability to different installation positions is reduced

Engineering Contradiction:
Improvecompressive force measurement reliabilityVSAvoidinstallation position flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The sensor's measurement capability is changed from orientation-dependent (compressive only) to orientation-independent (bidirectional). This parameter change allows the sensor to reliably measure forces regardless of installation position, simultaneously improving reliability and adaptability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The force sensor is designed with universal applicability across different installation orientations. It can measure both tensile and compressive forces in any position, making the system adaptable to various installation configurations while maintaining measurement reliability through consistent bidirectional sensing capability.

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

3Measurement precision

If pre-tensioning elements are added to enable compressive force measurement, then measurement capability is improved, but manufacturing effort increases

Engineering Contradiction:
Improvecompressive force measurement capabilityVSAvoidmanufacturing effort with pre-tensioning elements
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The fundamental parameter of the force sensor is changed to support bidirectional force measurement. This eliminates the need for additional pre-tensioning elements and complex mechanical arrangements, significantly simplifying the manufacturing process while enabling comprehensive force measurement capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and removes the complex pre-tensioning element system from the design. By using a bidirectional force sensor, the unnecessary pre-tensioning components are eliminated, reducing manufacturing effort and simplifying the overall device structure while maintaining full measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

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 reliable web tension measurement across various orientations with reduced design complexity, facilitating efficient and versatile installation in machines producing or treating fibrous webs like paper, cardboard, or tissue paper.

Implementation Method 1

A shear sensor, which measures shear loads, is particularly preferred as the force transducer. This allows both tensile and compressive loads between the two plates to be measured simultaneously with a single sensor.

Methodology Applied
Scientific EffectShear stress: Shear Stress

Data Source

PatentEP3850152B1Web-tension-measuring device, use of such, and a roller comprising a web-tension-measuring device
Publication Date: 2025.11.05 VOITH PATENT GMBH
  • EP3850152B1 patent drawingFigure 1

AI summary

A web-tension-measuring device having two plates, which can be rotated relative to one another about an axis of rotation, to be precise such that the one free end of the one plate can be moved towards, or away from, the corresponding, opposite free end of the other plate, having a force transducer arranged in the region of the free ends of the two plates, wherein the force transducer is arranged outside the axis of rotation and is designed such that, during movement of the free ends of the two plates towards one another, it detects a corresponding compressive loading arising from said movement and, during movement of the free ends away from one another, it detects a corresponding tensile loading between said two plates.