Stitch Cam Correction for Flat Knitting Loop Length Stability
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Solution Overview
Problem
Existing flat knitting machines face instability in stitch cam correction values across different needle beds, leading to variability in loop length and fabric texture, especially during rib knitting and garter knitting, due to differing angles and yarn tension changes.
Innovation Solution
A yarn length control device and method that allow for updating stitch cam correction values by either a common or dissimilar change amount depending on the needle bed, with specific adjustments for rib knitting to maintain constant texture and target loop length, by using a stitch cam correction unit to update values differently for front and rear stitches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the stitch cam correction value is updated by the same change amount for all needle beds, then the control process is simple, but the loop length becomes unstable especially at upper and lower needle beds
Solution Approach 1:
The patent applies local quality by differentiating the stitch cam correction value update strategy between different needle beds. Specifically, for rib knitting, the lower needle bed (where rear stitches are formed) uses a larger correction amount while the upper needle bed (where face stitches are formed) uses a smaller correction amount. This localized differentiation stabilizes loop length across all needle beds while maintaining manageable control complexity.
2Manufacturing precision
If the stitch cam correction value is updated aggressively to correct loop length deviations, then the target loop length is achieved faster, but the fabric texture becomes inconsistent
Solution Approach 1:
The patent applies parameter changes by adjusting the correction amount parameter differently for face stitches and rear stitches. For rib knitting, face stitches (upper needle bed) use a smaller correction amount to maintain texture consistency, while rear stitches (lower needle bed) use a larger correction amount to achieve target loop length. This differential parameter adjustment resolves both requirements simultaneously.
3Stability of the object's composition
If the stitch cam correction value is not updated during rib knitting, then the fabric texture remains constant, but the loop length deviates from target
Solution Approach 1:
The patent applies segmentation by separating the correction strategy into two independent control paths: one for face stitches and one for rear stitches. This allows selective updating of correction values - rear stitches can be updated with larger corrections to fix loop length, while face stitches use smaller corrections to preserve texture. The segmentation enables both goals to be achieved simultaneously.
Data Source
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AI summary
Stitch cams (9, 10) of each needle bed, in a flat knitting machine (2) provided with at least a pair of front and rear needle beds are controlled in accordance with a stitch cam correction value, and the stitch cam correction value is updated in accordance with a difference between loop length of stitches formed in the flat knitting machine (2) and a target value of loop length of the stitches. Setting is made as to whether to update the stitch cam correction value by a common change amount for each needle bed, or to update the stitch cam correction value by a dissimilar change amount varied depending on the needle bed, and the stitch cam correction value of each needle bed is updated according to the setting.