Variable Inertial Mass Deflecting Element for Weaving Machine Back Rest

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Solution Overview

Problem

Existing weaving machines with backrest devices struggle to maintain optimal warp thread tension across different weaving conditions and fabric densities, particularly requiring higher tensions for high weft density fabrics during reed beat-up to ensure tight thread alignment while minimizing tension during shed changes to prevent thread breakage.

Innovation Solution

The dynamic behavior of the coating bar's deflection element is adapted by varying its inertial mass through the addition or removal of masses, allowing for a range of 1.5 to 8 times the original mass, using spring elements connected to the machine frame to manage warp thread tension effectively during reed beat-up and shed changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the inertial mass of the deflecting element is minimized, then warp thread tension is reduced during shed changes, but warp thread tension is insufficient during reed beat-up for high weft density fabrics

Engineering Contradiction:
Improvewarp thread tensionVSAvoidadaptability to different weaving conditions
Core Design Contradiction:
ForceVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by making the inertial mass of the deflecting element variable rather than fixed. The system allows dynamic adjustment of mass to match different weaving conditions: low mass for high-speed weaving with low weft density, and high mass for reed beat-up of high weft density fabrics. This resolves the contradiction by enabling the system to adapt its force characteristics to different operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the inertial mass parameter of the deflecting element. Through interchangeable mass components, the system can change the mass parameter to optimize performance for different fabric types and weaving speeds, thereby achieving both low tension during shed changes and high tension during reed beat-up as needed.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If higher warp tensions are used during reed beat-up, then weft thread alignment is improved for high weft density fabrics, but thread breakage risk increases during shed changes

Engineering Contradiction:
Improveweft thread alignmentVSAvoidthread breakage prevention
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The dynamics principle enables the deflecting element to provide high resistance and thus high warp tension during reed beat-up of high weft density fabrics, ensuring precise weft thread alignment. During shed changes, the same system provides low resistance and low warp tension, preventing thread breakage. The dynamic mass adjustment allows the system to optimize both manufacturing precision and reliability for different phases of the weaving cycle.

Inventive Principle:
Principle #15Dynamics

3Force

If the inertial mass is increased, then resistance during reed beat-up is improved, but the system becomes less suitable for high-speed weaving

Engineering Contradiction:
Improveresistance during reed beat-upVSAvoidweaving speed
Core Design Contradiction:
ForceVSSpeed

Solution Approach 1:

The patent resolves this contradiction through dynamic mass adjustment. For high-speed weaving, the system uses low inertial mass to minimize resistance and maintain high weaving speeds. For reed beat-up of high weft density fabrics, the system switches to high inertial mass to provide the necessary resistance and force. This dynamic adaptability allows the system to optimize for either speed or force depending on the operational phase.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If a fixed mass design is used, then device complexity is reduced, but the system cannot adapt to different fabric types and weaving conditions

Engineering Contradiction:
Improvemass configurationVSAvoidadaptability to fabric types
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the inertial mass into a base mass and interchangeable additional mass components. This modular approach allows the system to maintain a simple base configuration while enabling adaptability through interchangeable components. The segmented mass design resolves the contradiction by keeping the core system simple while providing versatility through optional attachments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system enables parameter changes in inertial mass through interchangeable components, allowing adaptation to different fabric types and weaving conditions without fundamentally changing the device structure. This maintains relatively low device complexity while achieving high adaptability.

Inventive Principle:
Principle #35Parameter changes

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

This approach allows for adjustable warp thread tension, ensuring higher resistance during reed beat-up for high weft density fabrics and reduced tension during shed changes, preventing thread breakage and maintaining fabric quality across varying weaving conditions.

Implementation Method 1

The deflecting element is connected to the frame of the weaving machine via one or more spring elements in such a way that, when acceleration forces act on the deflecting element via the warp threads, inertial forces and spring forces become effective on the deflecting element.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the inertial mass effective during acceleration of the deflection element is changed in order to adapt the dynamic behavior of the batter bar to changing weaving conditions

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP3507405B1Method and device for changing the dynamic behaviour of a back rest of a weaving machine
Publication Date: 2020.06.17 LINDAUER DORNIER GMBH
  • EP3507405B1 patent drawingFigure 1
  • EP3507405B1 patent drawingFigure 2

AI summary

The invention relates to a method for changing the dynamic behaviour of a back rest of a weaving machine, and to a weaving machine having a back rest, wherein the back rest contains at least one deflecting element (2) for deflecting warp threads (1), wherein the deflecting element (2) is connected to the weaving machine via one or more spring elements in such a way that, when forces are applied to the deflecting element (2) via the warp threads (1), inertia forces and spring forces become active on the deflecting element (2). The inert mass acting on the deflecting element (2) is changed in order to adapt the dynamic behaviour of the back rest to altered weaving conditions in that parts of the deflecting element (2) or parts which are connected to the deflecting element (2) are replaced, removed or supplemented.