Buttonholing Sewing Machine Opening Width Control
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Solution Overview
Problem
Existing buttonholing sewing machines face challenges in forming high-quality double buttonholing seams, particularly in the second seam, due to insufficient cloth opening and needle drop issues, which affect the quality and integrity of the seam.
Innovation Solution
A buttonholing sewing machine with a control device that performs opening width varying control, allowing the press mechanism to increase the buttonhole opening width during the formation of the second buttonholing seam compared to the first, using a combination of air cylinders and air supply rate adjustments to enhance seam quality and prevent needle drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the opening width is kept constant during double buttonholing seam formation, then the first buttonholing seam can be formed properly with sufficient cloth opening, but the second buttonholing seam cannot be formed satisfactorily because the cloth has already been opened fully in the first sewing
Solution Approach 1:
The press mechanism is configured to dynamically adjust the opening width of the buttonhole during the double buttonholing seam formation process. Specifically, the mechanism maintains a first opening width during formation of the first buttonholing seam, then changes to a second opening width that is different from the first opening width during formation of the second buttonholing seam. This dynamic adjustment allows each seam to be formed under optimal conditions.
Solution Approach 2:
The invention changes the parameter of opening width between the first and second buttonholing seams. The control mechanism adjusts the opening width parameter to be different for each seam formation process, ensuring that the cloth is properly positioned and tensioned for each specific sewing operation, thereby resolving the issue of insufficient cloth opening effect in the second seam.
2Manufacturing precision
If the interval between parallel sets of stitches on the left side and the right side of a buttonhole is set small to increase the quality of sewing performance, then the sewing quality improves, but the needle may be dropped in the adjacent parallel sewing section beyond the buttonhole to close the buttonhole
Solution Approach 1:
The knife mechanism forms the buttonhole in the sewing object before the second buttonholing seam is formed. This preliminary action ensures that the buttonhole is pre-cut and positioned correctly, allowing the press mechanism to properly control the cloth opening width during the second seam formation, thereby preventing needle drops while maintaining small stitch intervals for high sewing quality.
3Device complexity
If the press mechanism maintains a constant opening width during both first and second buttonholing seam formation, then the mechanism operation is simplified, but the second buttonholing seam formation is insufficient due to lack of cloth opening effect
Solution Approach 1:
The press mechanism implements dynamic control of the opening width, transitioning from a first opening width during the first buttonholing seam formation to a second opening width during the second buttonholing seam formation. This dynamic adjustment, while increasing control complexity, is necessary to achieve satisfactory quality in the second buttonholing seam by restoring the cloth opening effect that was fully utilized in the first seam.
Data Source
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AI summary
A buttonholing sewing machine (1) in which a buttonholing sewing control is performed for formation of buttonholing seam. In performing a buttonholing sewing control, a control device (70) causes formation of a double buttonholing seam around a buttonhole and causes a knife mechanism (30) to form a buttonhole before formation of a second buttonholing seam and performs an opening width varying control of controlling a press mechanism (40) so that it makes the buttonhole opening width larger in forming the second buttonholing seam than in forming a first buttonholing seam. The thus-configured buttonholing sewing machine (1) can form a double buttonholing seam satisfactorily.