Latch Needle Width Reduction for Knitting Machine Wear
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Solution Overview
Problem
Existing latch needles in knitting machines suffer from increased wear and deflection due to manufacturing tolerances, leading to contact issues with sinkers and thread damage, particularly with hook-toothed needles that have a narrow latch head and sharp edges, resulting in faulty stitch formation and production defects.
Innovation Solution
A latch needle design with a latch head width of less than 95% of the needle shank, featuring parallel side surfaces forming a facetted latch head and a depression to accommodate the hook tip, ensuring a smooth transition and reducing the risk of thread damage, combined with a tapered latch shaft for reduced wear and improved movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a narrow latch head is used to avoid contact with adjacent sinkers, then the risk of contact and wear is reduced, but the half stitch may get stuck on the hook tip and stitch formation is interrupted
Solution Approach 1:
The latch head is designed with a width that is less than the width of the needle shank, creating a locally narrowed geometry only at the critical latch head region. This localized dimensional change allows the latch head to clear adjacent sinkers during oscillation while maintaining sufficient width at the hook tip area to prevent half stitch entanglement, thus resolving the contradiction between avoiding contact and ensuring reliable stitch formation
Solution Approach 2:
The invention addresses the spatial conflict by optimizing the latch head width in the transverse dimension relative to the needle shank width. By controlling the latch head width to be less than the needle shank width, the design creates sufficient clearance in the transverse direction to avoid sinker contact while maintaining adequate dimensions in the longitudinal direction to prevent thread entanglement, effectively using dimensional optimization to resolve the contradiction
2Ease of manufacture
If manufacturing tolerances are maintained within standard limits, then production cost is reduced, but the latch needle deflects from ideal position and contacts adjacent sinkers
Solution Approach 1:
The invention applies a localized geometric modification where the latch head width is specifically designed to be less than the needle shank width. This local dimensional control compensates for manufacturing tolerances and wear in the guide channel and latch bearing, ensuring that even with standard manufacturing variations, the latch head maintains sufficient clearance from adjacent sinkers throughout the oscillation range, thus resolving the contradiction between ease of manufacture and avoidance of harmful contact
Solution Approach 2:
The design incorporates a preemptive geometric buffer by making the latch head narrower than the needle shank. This creates an inherent clearance margin that compensates for anticipated wear and manufacturing tolerances before they cause problems. The narrowed latch head acts as a built-in cushion that prevents contact with adjacent sinkers even when tolerances accumulate over time, resolving the contradiction between standard manufacturing and avoiding contact
3Object-affected harmful factors
If the latch head width is reduced to avoid thread damage, then thread damage is minimized, but the latch head may slide laterally past the hook
Solution Approach 1:
The invention implements a differentiated width design where the latch head width is less than the needle shank width, creating a localized narrow region that minimizes thread damage risk. The parallel side surfaces of the latch head provide stable engagement with the hook tip, preventing lateral sliding while the reduced overall width avoids excessive contact with threads. This local quality differentiation resolves the contradiction between minimizing thread damage and maintaining stable positioning
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 design minimizes contact with adjacent parts, reduces thread damage, and enhances stitch formation quality by allowing smooth sliding of half stitches and reducing wear, thereby preventing faulty goods and improving knitting machine efficiency.
Implementation Method 1
The side surfaces are parallel to one another and extend over the entire latch head... The smooth transition and reduced risk of thread damage
Data Source
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AI summary
Latch needle for knitting machines has a shaft (20) and a stitch-forming section. A latch (9) is pivoted on the needle and fits over a hook on its end. The breadth (16) of the slot in the latch is below 95% of the breadth (11) of the shaft.