Spinning Draft Roller Stop Structure for Faster Roving Cutoff

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Solution Overview

Problem

Existing draft devices in spinning machines take an increased amount of time to stop the supply of roving due to the deep entry of the second arcuate wedge between the lower belt and the middle roller, which prolongs the rotation of the lower belt.

Innovation Solution

Incorporation of an apron guide roller with crowned roller members and a roving supply stop device that includes a back and middle roller stop members, utilizing a switching mechanism to swiftly block the rotation of the rollers upon detecting roving breakage, reducing the time required to stop the roving supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the second arcuate wedge deeply enters between the lower belt and the middle roller to stop the rotation, then the roving supply stop device can effectively stop the delivery of roving, but the time required to stop the rotation of the lower belt increases

Engineering Contradiction:
Improveeffectiveness of stopping roving deliveryVSAvoidtime required to stop lower belt rotation
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention divides the stopping function into two independent parts: the first arcuate wedge on the push plate handles the primary stopping action, while the second arcuate wedge on the support plate provides auxiliary stopping. This segmentation allows the system to achieve reliable stopping without requiring the second wedge to deeply enter, thus reducing stopping time while maintaining effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a support plate as an intermediary component that carries the second arcuate wedge. This support plate is disposed on the push plate, creating a hierarchical structure where the second wedge can provide stopping assistance without needing to deeply penetrate between the lower belt and middle roller, thereby reducing the time required for the stopping action.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the second arcuate wedge deeply enters between the lower belt and the middle roller, then the contact of the lower belt with the middle roller is interrupted, but the amount of roving delivered by the rotation of the lower belt increases

Engineering Contradiction:
Improveinterruption of lower belt contactVSAvoidamount of roving delivered
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The stopping function is segmented between two wedges: the first arcuate wedge provides the primary interruption of contact, while the second arcuate wedge provides supplementary stopping action. This segmentation allows the system to achieve reliable contact interruption without requiring deep entry, thus minimizing the amount of roving delivered during the stopping process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second arcuate wedge provides partial stopping action rather than requiring full deep entry. This partial action is sufficient to assist the first wedge in interrupting the contact between the lower belt and middle roller, thereby achieving the desired effect with reduced roving delivery.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4474541B1Draft device for spinning machine
Publication Date: 2026.03.18 TOYOTA INDUSTRIES CORP
  • EP4474541B1 patent drawingFigure 1
  • EP4474541B1 patent drawingFigure 2~3
  • EP4474541B1 patent drawingFigure 4~5

AI summary

A spinning machine (100) includes a draft device (10) provided with a roving supply stop device (30). The draft device (10) includes: a back roller unit (14) including a back bottom roller (14a) and a back top roller (14b); and a middle roller unit (12) including a middle bottom roller (12a), a middle top roller (12b), a middle bottom apron (21), and a middle top apron (22). The roving supply stop device (30) includes a back roller engaging portion (32) having a back roller wedge portion (32a), and a middle roller engaging portion (42) having a middle roller wedge portion (42a). The roving supply stop device (30) includes an apron guide roller (25) disposed upstream of the middle bottom roller (12a) and downstream of the back bottom roller (14a) in a traveling direction (X) of a roving (F). The middle bottom apron (21) is wound around the apron guide roller (25) at a position upstream of and away from the middle bottom roller (12a) in the traveling direction (X).