Thread Sensor Tubes for Circular Knitting Fault Detection
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Solution Overview
Problem
Existing thread feed devices for circular knitting machines with stripers are inadequate in detecting thread faults beyond breaks or ends, often leading to knitting errors due to insufficient shutdown time and inability to monitor thread defects like thickening, especially in fast-running machines.
Innovation Solution
A thread feeding device with standard feeders and thread guide tubes equipped with capacitive or optical sensors positioned at a distance from the knitting point, allowing for parallel monitoring of all threads to detect breaks, ends, and quality issues, enabling timely machine shutdown and preventing pattern errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If sensor devices are arranged close to the knitting point for quick detection, then response time is improved, but the machine cannot shut down in time before knitting errors occur in fast-running machines
Solution Approach 1:
The sensor devices are arranged in the thread guide tubes at a distance upstream from the knitting point, performing thread defect detection in advance before the thread reaches the knitting area. This preliminary detection allows sufficient time for machine shutdown while maintaining reliable defect detection capability.
2Reliability
If special strip feeders with shut-offs are used for thread monitoring, then thread break detection is improved, but other thread defects such as thickening cannot be detected
Solution Approach 1:
The sensor devices in the thread guide tubes are designed to detect multiple types of thread defects including breaks, ends, and thickening. This multi-functional sensor system replaces the limited special strip feeders while maintaining break detection capability and adding versatility to monitor various thread quality issues.
3Device complexity
If standard feeders are used instead of special strip feeders, then device complexity is reduced, but thread monitoring capability may be compromised
Solution Approach 1:
The thread guide tubes serve as intermediary elements between the standard feeders and the knitting point, incorporating sensor devices that enable comprehensive thread monitoring. This allows standard feeders to be used while maintaining reliable detection through the intermediary sensing system in the guide tubes.
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 effectively detects all thread faults, including thickening, allowing for timely machine shutdown and reducing knitting errors by monitoring thread presence, movement, and quality, thereby enhancing quality assurance.
Implementation Method 1
The thread sensor devices can preferably have capacitive or optical sensors
Implementation Method 2
The thread sensor devices can preferably have capacitive or optical sensors
Data Source
Figure 1
AI summary
A thread-feeding device for circular knitting machines having yarn-striping devices (14), which has thread-conducting tubes (10), per yarn-striping device (14), in a number which corresponds to the number of threads which can be processed by the yarn-striping devices (14), the thread-conducting tubes (10) respectively being disposed between a receiving means (11) for a thread bobbin and a striper feeder (12) which precedes the yarn-striping device (14) and being provided with a thread-sensor mechanism (13), the thread sensor mechanisms (13) of all thread-conducting tubes (10) assigned to one knitting position (15) being evaluatable in common by one monitoring device and a stop signal being generatable by the monitoring device for the machine control upon detection of a thread fault.