Web Guiding Device with Flexible Frame for Skewed Feed Correction

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Solution Overview

Problem

Existing web guiding devices are complex, expensive, and prone to malfunctions when correcting skewed infeeds of material webs, as they require external control and are not effective in compensating for asymmetric tensile forces.

Innovation Solution

A web guiding device with pivotably mounted frame elements and a second axle connected via a fixing element, which uses the asymmetrical tensile forces to create a torsion that deflects the web guide roller, balancing the web tension without external control, utilizing flexible materials and joint ball bearings for stability and ease of movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If web guide rollers with integrated differential gears are used to compensate for skewed feed, then the web guidance is corrected, but the device becomes complex and expensive

Engineering Contradiction:
Improveweb guidance correctionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the active control system (sensors and actuators) from the web guiding device and replaces it with a passive mechanical compensation mechanism. The frame elements and second axis inherently respond to asymmetric tensions through their flexible design, eliminating the need for external control systems while maintaining web guidance correction functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The web guiding device uses the asymmetric tension forces from the skewed web feed itself to trigger the compensation mechanism. The flexible frame elements and second axis automatically deflect in response to the applied forces, creating a self-regulating system that corrects web guidance without requiring external sensors or actuators to detect and respond to the skew.

Inventive Principle:
Principle #25Self-service

2Reliability

If active actuators (pneumatic, hydraulic, or electric) are used for active correction of web guidance, then skewed feed is corrected, but the device becomes expensive and prone to malfunctions

Engineering Contradiction:
Improveskewed feed correctionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces complex active mechanical systems (pneumatic, hydraulic, or electric actuators) with a simpler passive mechanical system. The flexible frame elements and second axis provide the necessary adjustment through their inherent flexibility, eliminating the need for powered actuators while maintaining the ability to correct skewed feed.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention removes the active control components (sensors and actuators) entirely from the system, retaining only the essential passive mechanical structure. The flexible frame and second axis provide the correction function without requiring external control systems, thereby reducing complexity and cost while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If dancers are used to compensate for symmetrical web tensions, then tension is balanced, but they are not suitable for compensating for skewed feeds

Engineering Contradiction:
Improvetension balancingVSAvoidskewed feed compensation capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention introduces asymmetric flexibility to the frame structure through the second axis connecting the frame elements. This asymmetric design allows the structure to respond differently to tensions on opposite sides of the web, enabling compensation for skewed feeds while maintaining tension balancing capabilities. The flexible second axis creates a moment in response to asymmetric forces, deflecting the web guide roller to correct the skew.

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 device effectively corrects asymmetrical web feeds by balancing tensile forces internally, ensuring a straight and evenly tensioned web output without the need for external sensors or actuators, resulting in a cost-effective and reliable solution.

Implementation Method 1

The frame elements and/or the second axis are designed to be flexible. The necessary flexibility can be achieved through appropriate material selection and by adjusting the material thickness depending on the tensile forces occurring in a specific processing machine.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3177554B1Web guiding device and device for processing a web of material
Publication Date: 2019.08.14 LEONHARD KURZ STIFTUNG & CO KG
  • EP3177554B1 patent drawingFigure 1
  • EP3177554B1 patent drawingFigure 2
  • EP3177554B1 patent drawingFigure 3~4

AI summary

The invention relates to a web guiding device (3) for guiding a web of material (2), in particular film web, comprising a first frame element (31) and a second frame element (32) which - are mounted on a first shaft (33) in such a way as to be pivotable in first end regions (311, 321), - are connected in the second end regions (321, 322) by means of a rotatably mounted web guiding roll (34), and - are connected by means of a second shaft (35) that is attached to the first shaft (33) by means of a fastening element (37).