Variable Thread Consumption in Sewing Machine Cutters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sewing machines with processor-controlled thread cutters have a fixed thread length consumption, limiting the adjustment of thread length during cuts, which restricts fine adjustments and increases the risk of thread being pulled out of the needle eye.
Innovation Solution
A method that allows for variable thread length consumption during cuts by using a sewing machine's processor to control the thread cutter, enabling the consumption of a predetermined thread length within a specified interval, which can be used to adjust thread length on both sides of the fabric.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed thread length consumption is used for cuts, then the thread cutter operation is simple, but the ability to adjust thread length for fine adjustments and prevent thread being pulled out is limited
Solution Approach 1:
The thread cutter control system transitions from a fixed, static thread length consumption to a dynamic, variable system where the thread length can be adjusted in real-time. The processor-controlled thread fetcher can vary the thread length within a predetermined interval, allowing the system to adapt to different sewing conditions such as colour changes and fine adjustment requirements.
Solution Approach 2:
The invention changes the parameter of thread length consumption from a fixed value to a variable parameter that can be controlled by the processor. By allowing the thread length to vary within a predetermined interval, the system can optimize thread usage for different sewing scenarios while maintaining control through the processor.
2Manufacturing precision
If a fixed thread length consumption of around 25 mm is used, then the thread cutter operation is standardized, but the possibility for fine adjustment of thread length consumed during cuts is limited
Solution Approach 1:
The processor-controlled thread fetcher system incorporates feedback mechanisms that allow the system to monitor and adjust thread length consumption based on actual sewing conditions. This enables precise control for fine adjustments while maintaining ease of operation through automated processing.
Solution Approach 2:
The system performs preliminary actions by pre-calculating and preparing variable thread length settings within a predetermined interval before the actual cutting operation. This allows for precise thread length adjustment to be ready when needed, such as for colour changes, while maintaining simple operation through automated execution.
3Reliability
If the thread length consumed in a cut is not increased, then the sewing operation is efficient, but the risk of thread being pulled out of the needle eye increases
Solution Approach 1:
The thread length consumption is made dynamic and variable rather than fixed. The processor-controlled system can increase thread length when needed to prevent needle eye pull-out, while maintaining efficient sewing operations during normal conditions. This dynamic adjustment resolves the contradiction between reliability and productivity.
Data Source
AI summary
A method and a device for cutting at least an upper thread of a sewing machine provided with a fabric clamping member (20), wherein a length of the thread consumed for a cut can be set within a predetermined interval. The method for cutting at least the upper thread (4) of a sewing machine (1) includes the steps: feeding a predetermined length x of said upper thread (4) utilizing a thread feeder (15), pulling out the upper thread (4) said predetermined length utilizing a displacement of said fabric clamping member (20) from a current position to a second position executing by means of a sewing machine processor (C) program sequences stored in a memory (M) for controlling a thread cutter (10) to perform a cut of at least said upper thread (4).