V-Groove Guide Roller Yarn Feeding Mechanism
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Solution Overview
Problem
Existing yarn feeding mechanisms in flat knitting machines face challenges in preventing yarn slack without excessively increasing tension, which can lead to adverse effects such as broken yarns or narrowed stitches.
Innovation Solution
A yarn feeding mechanism featuring V-groove guide rollers with inclined rotation shafts and an active yarn feeder, which twists the folded yarn to prevent slack without excessive tension, using a sine curve design for the groove valleys and adjustable inclined angles to accommodate different yarn types and conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tension of the folded yarn is excessively increased to eliminate slack yarn, then yarn slack is prevented, but the yarn may be easily broken or stitches may be narrowed
Solution Approach 1:
The V-groove guide roller employs a curved V-shaped groove geometry instead of a straight guide. The yarn follows the curved path from one inclined surface through the valley to the other inclined surface, which naturally introduces twisting action. This curvature-based design prevents yarn slack through the twisting effect without requiring excessive tension, thereby avoiding yarn breakage and stitch narrowing.
2Reliability
If the tension of the folded yarn is excessively increased to eliminate slack yarn, then yarn slack is prevented, but stitches may be narrowed
Solution Approach 1:
The curved V-groove path causes the yarn to twist naturally as it passes through the roller. This twisting action eliminates yarn slack through mechanical reconfiguration rather than tension, thereby preventing stitch narrowing and maintaining stitch quality without compromising manufacturing precision.
3Reliability
If a top tension device or side tension device is provided to apply tension to the yarn, then yarn slack is prevented, but the complexity of the device increases
Solution Approach 1:
The invention extracts the yarn slack prevention function from complex tensioning devices and implements it through a simple V-groove guide roller with inclined shaft. The roller's geometric design inherently provides the slack prevention through yarn twisting, eliminating the need for additional tension devices and reducing overall device complexity.
Solution Approach 2:
The V-groove guide roller acts as an intermediary element that transforms the yarn path geometry to achieve twisting and slack prevention. Instead of using complex active tensioning mechanisms, the roller mediates between the yarn feed and the knitting process through its passive geometric configuration, simplifying the overall system.
Data Source
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AI summary
Upstream-side and downstream-side V-groove guide rollers (24, 25) having substantially V-shaped grooves (241, 251) are rotatably supported in a feeding path in which yarns are formed into a folded yarn by a yarn combining device and is supplied to a yarn carrier. Shafts (242, 252) of the V-groove guide rollers (24, 25) are inclined relative to a direction perpendicular to the feeding path so that the folded yarn is twisted while being rolled from one inclined surfaces (243A, 253A) of the inclined surfaces (243A, 243B, 253A, 253B) of the grooves (241, 251) to valleys. Further, lines (X, Y) tracing the valleys of the grooves (241, 251) of the V-groove guide rollers (24, 25) in a circumferential direction forms one cycle of a sine curve for one turn of the V-groove guide rollers (24, 25) in an expanded state.