Machine Knitting Needle Convex Shank Contour Design
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Solution Overview
Problem
High-speed operation of machine knitting needles leads to excessive wear and breakage due to the abrupt impact of the latch striking the shank, which is exacerbated by the concave shank contour design causing high yarn tension and friction.
Innovation Solution
A machine knitting needle with a convex shank contour between the hook and needle cheek, reducing the load on the latch and shank by allowing the yarn to rise gradually, thus decreasing the angle of friction and the speed at which the latch meets the shank, preventing abrupt impacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the knitting speed is increased to improve productivity, then the output increases, but the latch strikes the shank at high speed causing excessive wear and breakage
Solution Approach 1:
The shank contour is changed from concave to convex (nonconcave), creating a rounded, curved surface that gradually guides the yarn and loop. This curvature eliminates the abrupt transition point that caused sudden yarn tension changes and latch impact, allowing the system to operate at higher speeds without damage.
Solution Approach 2:
The invention changes the geometric parameters of the shank contour by eliminating the concave region and throat transition. This parameter change modifies the yarn path and friction characteristics, resulting in more uniform yarn tension and reduced latch striking speed, thereby enabling higher knitting speeds with improved reliability.
2Ease of operation
If the concave shank contour is used to guide the yarn, then the yarn path is defined, but the angle of friction increases and causes high yarn tension leading to latch impact
Solution Approach 1:
The convex shank contour provides continuous yarn guidance through a smooth curved surface, eliminating the need for the concave throat geometry. The rounded profile maintains effective yarn routing while distributing friction forces more uniformly, preventing the buildup of high yarn tension that leads to latch impact.
3Speed
If the latch is allowed to swing freely with intrinsic inertia, then the latch mechanism operates at high speed, but the latch strikes the shank with high impact causing wear and breakage
Solution Approach 1:
The convex shank contour acts as a preventive measure by modifying the yarn and loop behavior before the latch reaches the back position. The gradual rise and reduced friction cause the loop to move more uniformly, which in turn reduces the latch acceleration and striking speed, cushioning the impact before it occurs.
Solution Approach 2:
The invention converts the harmful high-speed latch impact into a beneficial low-impact operation by using the convex shank contour to modify the yarn dynamics. The same latch swinging motion that previously caused damage is now harnessed at controlled speeds, with the contour geometry transforming the harmful kinetic energy into useful yarn guidance and loop formation.
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
This design increases the operating speed of the machine knitting needle while reducing wear and breakage, enhancing the durability and quality of the knitting process by maintaining uniform yarn sliding speed and minimizing impetus transmission to the latch.
Implementation Method 1
the angle of friction of the yarn increases steadily during its motion in the direction of the needle cheek. At the transition from the shank contour, that is, from the cheek elevation, to the needle cheek, the angle of friction is relatively large.
Data Source
AI summary
The machine knitting needle of the invention, beginning at its hook (3), between the hook (3) and its latch bearing (9), has a convex or at least not concave shank contour, which defines the inner hook contour and on one end (18) adjoins the concave inner hook contour directly. It is attained as a result that the elevation angle which a yarn (23), located in the hook (3), must overcome if it is to slide on the shank does not increase at any point along the inner contour (17). Preferably, it even decreases steadily. It thus has its maximum value inside a space which is defined on the one hand by the inner hook contour (15) and on the other by a plumb line (L) or (L1) which is dropped, from the hook tip (12) or its tapering portion (11), onto the needle back (16), or if the needle back is not oriented parallel to the direction of motion of the machine knitting needle, onto the arrow that defines the direction of motion. The convex or at least not concave shank contour (17) merges continuously with the likewise convex contour of the needle cheek (7).