Spinning Draft Device Apron Control for Blending Ratio
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Solution Overview
Problem
Existing draft devices for spinning machines require complex structures to change the blending ratio of two different types of rovings, often necessitating additional rollers or split rollers, which complicates the spinning process and limits flexibility.
Innovation Solution
A draft device with two rows of apron pairs behind the front rollers, where the middle and back apron pairs are controlled for start and stop operations, allowing the blending ratio of two different types of rovings to be changed without adding complexity, by ensuring the thickness relationship between apron pairs prevents rotation failure and allows for continuous spinning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If independent draft rollers are provided for respective rovings to enable independent drafting, then the ability to change blending ratio is improved, but the device complexity increases
Solution Approach 1:
The patent merges the drafting functions for two different rovings into a single shared draft roller. The first and second rovings are drafted by the same draft roller along with the common front roller, eliminating the need for separate draft rollers for each roving type. This reduces structural complexity while maintaining the ability to independently control roving supply through separate bottom rollers.
2Adaptability or versatility
If the middle top roller and middle bottom roller are split into right and left halves with separate drive sources, then the ability to supply different rovings is improved, but the device complexity increases
Solution Approach 1:
The patent combines the middle top roller and middle bottom roller into a single integrated unit rather than splitting them into separate right and left halves. This unified structure supplies both first and second rovings without requiring separate drive sources for different sections, thereby reducing mechanical complexity while maintaining functional versatility.
Solution Approach 2:
The middle roller unit is designed to perform multiple functions: it can supply the first roving when the first bottom roller rotates, and supply the second roving when the second bottom roller rotates. This multi-functional design eliminates the need for separate roller sections while maintaining the ability to handle different roving types independently.
3Device complexity
If one roving is converged with the other before reaching the middle roller, then the structure is simplified, but the ability to spin with only one roving is lost
Solution Approach 1:
The patent implements a dynamic roving supply system where the convergence of rovings is not fixed but can be dynamically controlled. The middle roller can selectively receive and process either the first roving or the second roving based on the rotation of the respective bottom rollers. This dynamic configuration allows the system to simplify structure when both rovings are used while maintaining the flexibility to process only one roving type when needed.
Data Source
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AI summary
A draft device for a spinning machine that spins a yarn while changing the blending ratio of two different types of rovings has a middle bottom roller and a middle top roller, a back bottom roller and a back top roller, a middle apron pair, and a back apron pair. The middle apron pair is supplied with a first roving and has a middle bottom apron wrapped around the middle bottom roller and a middle top apron wrapped around the middle top roller. The middle top apron is driven by the middle bottom roller in a state pressed by the middle bottom apron. The back apron pair is supplied with a second roving and has a back bottom apron wrapped around the back bottom roller and a back top apron wrapped around the back top roller. The back apron pair is driven by the back bottom roller in a state pressed by the back bottom apron.