Differential-Speed Trimming Discs for Uniform Tobacco Rope Cutting

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Solution Overview

Problem

Existing trimming devices for making continuous ropes in the tobacco industry suffer from imprecise and uneven cutting due to trimming discs moving at the same tangential speed, leading to compression and variability in tobacco particle size, affecting the quality and combustion characteristics of the final product.

Innovation Solution

The trimming device employs two counter-rotating trimming discs with different tangential speeds, achieved through varying angular speeds and/or diameters, to optimize the cutting action and prevent compression, ensuring uniform thickness and improved cutting efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the trimming discs move at the same tangential speed as the continuous rope, then the cutting action is simplified, but the cutting precision deteriorates and compression occurs

Engineering Contradiction:
Improvecutting mechanism complexityVSAvoidrope thickness uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by varying the tangential speeds of the two trimming discs relative to each other and to the rope feed speed. Specifically, one trimming disc moves at a speed different from the rope feed speed while the other moves at the rope feed speed, creating a speed differential that enables precise cutting without compression. This parameter variation resolves the contradiction by allowing controlled material removal while maintaining thickness uniformity.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the trimming discs move at the same tangential speed, then the structural symmetry is maintained, but compression and crushing of material occurs

Engineering Contradiction:
Improvestructural symmetryVSAvoidmaterial compression and crushing
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies asymmetry by intentionally creating a speed differential between the two trimming discs. While the mechanical structure remains symmetric for ease of manufacture, the operational parameters are made asymmetric: one disc rotates at a speed matching the rope feed rate while the other rotates at a different speed. This asymmetric operation eliminates compression and crushing effects while maintaining the benefits of symmetric structural design.

Inventive Principle:
Principle #4Asymmetry

3Ease of operation

If the cutting edges move at the feed speed of the continuous rope, then the cutting action is simplified, but the cutting efficacy deteriorates

Engineering Contradiction:
Improvecutting operation simplicityVSAvoidcutting quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the trimming disc speeds variable rather than fixed at the rope feed speed. The system dynamically adjusts the tangential speeds of the trimming discs, allowing one disc to move at the rope feed speed while the other moves at a different speed. This dynamic speed variation optimizes cutting efficacy by preventing material compression while maintaining operational simplicity through the coordinated action of the two discs.

Inventive Principle:
Principle #15Dynamics

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 more precise and uniform cutting process, enhancing the quality of the finished product and reducing the need for cleaning interventions, while being suitable for both traditional cigarettes and smoking articles without combustion.

Implementation Method 1

said feed means comprising a suction conveyor configured to keep the rope suspended, in particular, by means of pneumatic suction

Methodology Applied
Scientific EffectPneumatic suction: Suction

Data Source

PatentEP4646941A1Trimming device and method for making a rope of the tobacco industry
Publication Date: 2025.11.12 GD SPA
  • EP4646941A1 patent drawingFigure 1~1A
  • EP4646941A1 patent drawingFigure 2~2A
  • EP4646941A1 patent drawingFigure 3~3A

AI summary

Trimming device (1) for making a rope of the tobacco industry, comprising feed means (2) configured to feed a continuous rope (C) of the tobacco industry along a feed path (L), at a respective feed speed. The device comprises a first trimming disc (10) and a second trimming disc (20), juxtaposed along said feed path (L) so as to engage the continuous rope (C). The trimming discs (10, 20) have respective cutting edges (11, 21) configured to perform a coordinated longitudinal cutting action on the rope (C), so as to separate an excess portion of the rope (C). The device (1) is configured so that the cutting edges (11, 21) of the trimming discs (10, 20) are moved at different tangential speeds.