Sewing Machine Buttonhole Cutting Using Submillimeter Fabric Offsets
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Solution Overview
Problem
Existing buttonhole sewing machines produce suboptimal results, particularly with resilient fabrics, due to incompletely cut residual fibers and undesired alterations in the buttonhole shape during multiple cuts.
Innovation Solution
A method involving a displacement of the fabric by less than 1 mm relative to the cutting device between initial and subsequent cuts, with varying offset paths and directions to improve cutting quality, and a sewing machine equipped with a control/regulating device to execute this method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple cuts are performed to create a buttonhole, then the cutting length is achieved, but residual fibers remain and cutting quality deteriorates
Solution Approach 1:
The patent applies parameter changes by varying the displacement between successive cuts. Specifically, the fabric is displaced by a first distance for the first recut and by a second distance (different from the first) for the second recut. This variation in displacement parameters prevents identical cutting edge sections from interacting with identical fabric sections, thereby eliminating residual fibers and improving cutting quality.
2Manufacturing precision
If the fabric is displaced between cuts to improve cutting quality, then residual fibers are reduced, but the buttonhole shape may be altered
Solution Approach 1:
The patent carefully controls the displacement parameters to be within specific ranges (first distance and second distance both less than 1 mm) to achieve parameter optimization. This controlled variation improves cutting quality while maintaining the desired buttonhole shape.
Solution Approach 2:
The patent applies different displacement distances for different recuts (first recut uses first distance, second recut uses second distance). This localized variation in displacement quality ensures that each recut addresses specific cutting issues without uniformly altering the buttonhole shape.
3Manufacturing precision
If recutting is performed with small displacement, then cutting precision is improved, but the process time increases
Solution Approach 1:
The patent performs recuts with small displacements (less than 1 mm) only when necessary to eliminate residual fibers, rather than performing excessive recuts. This partial action approach achieves the required cutting precision while minimizing additional process time.
Data Source
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AI summary
When creating a buttonhole or lace-up hole in fabric (21) using a sewing machine, an initial cut (22) is first made in the fabric (21) by a cutting device of the sewing machine. The fabric (21) is then displaced relative to the cutting device along a displacement direction (y) by a displacement path (Δy) that lies between 0 mm and less than 1 mm. With the fabric (21) displaced, at least one further cut (23) is made. This results in the neatest possible buttonhole or lace-up hole.