Sawtooth Wire Tooth Profile for Fiber Delivery

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Solution Overview

Problem

Conventional sawtooth wires for spinning preparation machines are inefficient in delivering fiber material to downstream locations due to fiber accumulation in the transition areas between teeth, leading to reduced processing efficiency and increased waste.

Innovation Solution

A sawtooth wire design featuring a tooth base with a support edge and a row of teeth arranged to minimize fiber accumulation, where each tooth has a unique geometric configuration with sections that guide fibers efficiently, including a concave second section merging into a third section, and a reversal point with a tangent that defines a distance greater than half the tooth tip to tooth side distance, preventing fiber jamming and enhancing fiber delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the inter-tooth space distance is reduced to allow the sawtooth wire to be bent around the roller, then the sawtooth wire can be successfully wound onto the roller, but fiber material accumulates in the transition zone between teeth

Engineering Contradiction:
Improveability to wind sawtooth wire onto rollerVSAvoidfiber delivery efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies curvature by designing the tooth face with a concave second section that creates a specific geometric profile. This curved geometry guides fibers away from the inter-tooth space and prevents accumulation, while the overall tooth structure maintains the necessary flexibility for winding onto the roller. The concave curvature of the second section specifically addresses the fiber accumulation problem by creating a flow path that directs fibers toward the tooth tip rather than allowing them to collect in the transition zone.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If the second section of the tooth face is made concave to guide fibers away from the inter-tooth space, then fiber accumulation is reduced, but the tooth geometry becomes more complex

Engineering Contradiction:
Improvefiber delivery efficiencyVSAvoidtooth geometric complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The tooth face is segmented into four distinct sections (first, second, third, and fourth sections), each with a specific geometric function. The concave second section is one segment of this divided structure, designed to guide fibers away from the inter-tooth space. By segmenting the tooth face into functional zones, the patent achieves effective fiber guidance while maintaining a systematic and manufacturable geometry that balances complexity with performance.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the tangent length from the reversal point to the tooth side is increased to prevent fiber jamming, then fiber flow is improved, but the tooth tip height relative to the entire tooth height is reduced

Engineering Contradiction:
Improvefiber processing efficiencyVSAvoidtooth tip height ratio
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The patent optimizes specific geometric parameters of the tooth structure, including the tangent length from the reversal point to the tooth side and the relative heights of different tooth sections. By carefully adjusting these parameters, the design achieves a balance where the tangent length is sufficient to guide fibers effectively and prevent jamming, while the overall tooth geometry maintains appropriate proportions. The parameter optimization ensures that the concave second section provides adequate fiber guidance without compromising the functional tooth tip height.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3497271B2Card wire
Publication Date: 2025.01.08 TRUETZSCHLER GRP SE
  • EP3497271B2 patent drawingFigure 1a~1c
  • EP3497271B2 patent drawingFigure 2~5

AI summary

A sawtooth wire (1) is configured to be fitted onto a spinning preparation machine roller along the outer circumference thereof and transverse to the axis of rotation. Same has a tooth base (2) with a contact edge (4) which extends along the longitudinal extension of the wire (1), as well as a row of teeth which is formed on a tooth side (5) of the tooth base (2) facing away from the contact edge (4). The row of teeth extends along the longitudinal extension of the wire (1), when extended, and comprises teeth (3) which are arranged in a row in such a way that they protrude from the tooth side (5) substantially perpendicular to the longitudinal extension. Each tooth (3) has a tooth tip (6) pointing along the longitudinal extension and in the same direction, a parallel direction or an acutely angled direction to the tooth side (5) as the tooth tips of the other teeth (3), and a tooth face (20) that extends from the tooth tip (6) in one section (21) towards the tooth side (5) and towards the tooth back (10). The section (21) transitions into a concave section (22), the end of which, which is at a distance from the section (21), points towards the tooth side (5) and away from the tooth back (10). The section (22) transitions into a section (23) which extends towards the tooth side (5) and away from the tooth back (10). The section (23) transitions into a concave section (24), the end of which, which is at a distance from the section (23), points along the longitudinal extension and away from the tooth back (10). The section (24) transitions into a tooth back (10) of the next tooth (3). There is a turning point in the section (22), at which a tangent at the section (22) runs perpendicular to the tooth side (5) with a length (hu) from the turning point to the tooth side (5) along the tangent that is greater than or equal to half the distance (hz) between the tooth tip (6) and the tooth side (5).