Knitting Machine Loop Transfer Mechanism for Productivity
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Solution Overview
Problem
Existing methods for closing tubular knitted articles, such as hosiery, on circular knitting machines either reduce machine productivity or require complex and precise apparatuses for transferring articles to sewing or looping stations.
Innovation Solution
A method and apparatus that includes a pick-up device, handling device, turner, and sewing or looping head to close the axial end of tubular knitted articles directly on the machine, ensuring high precision and reliability without penalizing machine productivity, featuring a pick-up device that moves from the machine to a sewing or looping station to handle and close the article efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If closure operation is performed directly on the machine at the beginning or end of production, then closing operation can be integrated, but machine productivity is significantly reduced because the machine cannot produce a new article during closure
Solution Approach 1:
The article is prepared for closure while still on the knitting machine before the machine stops production. The pick-up device engages with the needles and loops are transferred to the handling device while the machine can continue or resume production, eliminating the need to wait for machine downtime.
Solution Approach 2:
A pick-up device with movable pick-up members acts as an intermediary between the knitting machine needles and the handling device. This intermediary mechanism enables smooth transfer of loops from the machine to the closure station without stopping production, resolving the conflict between automation integration and productivity maintenance.
2Productivity
If article transfer apparatus is used to move article from production machine to looping station, then closure can be performed separately, but complex apparatuses are required to ensure extremely precise operation
Solution Approach 1:
The transfer mechanism is segmented into discrete components: pick-up members that engage individually with needle stems, movable radial elements that control pick-up member positioning, and a handling device with spikes that receive the loops. This segmentation allows each component to perform its function simply and reliably without requiring complex integrated apparatus.
Solution Approach 2:
The pick-up members are made movable radially with respect to the pick-up device body, allowing them to dynamically adjust their position to engage with needle stems at the correct location. This dynamic capability simplifies the overall apparatus by replacing complex fixed positioning mechanisms with a simple movable element that adapts to the needle arrangement.
3Measurement precision
If pick-up members are fixed on the pick-up device body, then structure is simple, but precision in engaging needle stems is insufficient
Solution Approach 1:
The pick-up members are designed to move radially with respect to the pick-up device body, transforming them from fixed static elements to dynamic adjustable elements. This movement capability enables precise engagement with needle stems at the correct radial position, significantly improving pick-up precision without requiring overly complex positioning systems.
Solution Approach 2:
The radial position of the pick-up members can be changed as a parameter to adjust their engagement point on the needle stems. By varying this parameter, the system achieves precise engagement with needle stems located at different positions, improving measurement precision while maintaining relatively simple device structure.
Data Source
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AI summary
A method and an apparatus for closing a tubular knitted article at one of its axial ends, at the end of its production cycle on a circular knitting machine for hosiery or the like. The method consists in ending the production of an article (101) at one of its axial ends. The article (101) is then picked up from the machine (100) and transferred to a handling device (60) located in a sewing or looping station (102) that is spaced laterally with respect to the machine (100). The pick-up is performed by transferring individually the loops of the last row of knitting from the needles (123) of the machine (100) to spikes (62) of the handling device (60), which has an annular body composed of two semiannular elements (63a, 63b), one of which can be turned over with respect to the other about a diametrical axis (64), The article (101) is then turned, and one of the two semiannular elements (63a, 63b) is turned over with respect to the other one, so that the spikes (62) of one semiannular element face, and are aligned with, the spikes (62) of the other semiannular element. The loops of knitting arranged on the spikes (62) of one semiannular element are transferred to the spikes (62) of the other semiannular element so that each spike of the latter semiannular element supports a pair of loops of knitting. One then proceeds by joining, by sewing or looping, the pairs of loops of knitting, closing the axial end of the article engaged with the handling device. The article (101) is then disengaged from the handling device (60) and removed.