Motor-Driven Thread Tension Apparatus for Sewing Machines
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Solution Overview
Problem
Existing thread tension systems for sewing machines are not adjustable and fail to maintain consistent tension as thread is removed, and lack effective thread break detection, leading to suboptimal stitching and potential thread breakage during sewing.
Innovation Solution
An independent thread tension apparatus with a motor and digital controller that adjusts thread tension dynamically and includes a thread break detector to stop the sewing machine upon thread breakage, allowing for adjustable tension and immediate detection of thread breaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If mechanical devices using springs are used to release thread from a thread spool, then thread tension is provided, but the tension is not adjustable and cannot account for tension variances as more thread is removed
Solution Approach 1:
The patent applies dynamics by replacing static spring-based tension mechanisms with a dynamic motor-driven system. The motor and controller actively adjust the thread support position in real-time, allowing tension to be maintained consistently even as thread is consumed from the spool. This dynamic adjustment capability resolves the contradiction by enabling both adaptability (tension adjustment) and managing complexity through automated control.
Solution Approach 2:
The patent utilizes parameter changes by allowing the system to modify the position of the thread support dynamically. As thread is removed from the spool, the controller adjusts the motor position to compensate for changes in thread length and tension characteristics. This parameter adjustment ensures consistent tension throughout the sewing process, addressing the limitation of non-adjustable spring mechanisms.
2Reliability
If traditional thread tension devices are used, then they are simple in construction, but they lack rapid thread break detection capability
Solution Approach 1:
The patent implements feedback by incorporating a motor controller that continuously monitors the motor's operation. When thread breaks, the sudden change in motor load or rotation is detected by the controller, which then triggers an immediate stop signal to the sewing machine. This feedback mechanism provides reliable thread break detection while managing complexity through the use of existing motor control electronics.
Solution Approach 2:
The system applies self-service by using the motor's own operational parameters (current, speed, or position) as the detection mechanism for thread breakage. Rather than adding separate complex detection hardware, the controller leverages the motor's inherent operational data to detect breaks, thereby improving reliability without significantly increasing device complexity.
3Manufacturing precision
If spring-based tension devices are used, then they are easy to manufacture, but they cannot maintain consistent tension as thread is removed from the spool
Solution Approach 1:
The patent replaces the mechanical spring-based tension system with an electromechanical system consisting of a motor and controller. This substitution enables precise control over thread tension through electronic means, ensuring consistent tension as thread is consumed. The trade-off in manufacturing complexity is offset by the superior performance and precision gained through this mechanical-to-electromechanical transition.
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 apparatus ensures consistent thread tension across various sewing machines, preventing thread breakage and reducing the need for manual intervention by automatically stopping the machine upon thread breakage, resulting in improved stitching quality and efficiency.
Implementation Method 1
A motor is connected with the thread support and a controller is connected with the motor such that the controller operates to move the thread support in a first direction as thread is pulled off the thread support in a second direction opposite to the first direction such that a selected tension is added to the thread
Data Source
AI summary
An independent thread tension apparatus and method has a thread support where the thread support releasably retains thread. A motor is connected with the thread support and a controller is connected with the motor such that the controller operates to move the thread support in a first direction as thread is pulled off the thread support in a second direction opposite to the first direction such that a selected tension is added to the thread.