Double Cylinder Circular Machine Automated Sock Pickup
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Solution Overview
Problem
Double-cylinder circular machines for hosiery face challenges in automating the pickup of tubular articles due to the presence of curved knockover sinkers, which prevent the lifting of needles to the drop stitch position, making it difficult to engage pickup elements with the last row of knitting.
Innovation Solution
A method and machine design that simplifies the actuation of needle cylinders and knockover sinkers, allowing for precise automated pickup by using a rotary motion and central cam activation, enabling the use of a pickup device with elements engageable below the upper latch of the needles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If curved knockover sinkers are used in double-cylinder circular machines, then the knitting process is maintained, but the lifting of needles to the drop stitch position is prevented
Solution Approach 1:
The invention introduces a movable cam mechanism that dynamically adjusts the knockover sinker position. The cam can be shifted between a first position during knitting (where sinkers are curved and engaged) and a second position for pickup (where sinkers are disengaged, allowing needle lifting). This dynamic reconfiguration resolves the contradiction by making the sinker configuration adaptable rather than fixed.
Solution Approach 2:
The invention performs preliminary action by shifting the cam to the second position before the pickup operation begins. This preliminary repositioning of the cam and disengagement of sinkers prepares the system in advance to allow needle lifting to the drop stitch position, eliminating the conflict between sinker engagement and needle lifting requirements.
2Extent of automation
If pickup elements are engaged below the upper latch of needles, then automated pickup is enabled, but the presence of engaged sinkers prevents loop positioning
Solution Approach 1:
The movable cam mechanism enables dynamic switching between knitting mode (sinkers engaged, precise loop formation) and pickup mode (sinkers disengaged, loops positioned for pickup). This resolves the contradiction by separating the two functions temporally and spatially, allowing both automated pickup and manufacturing precision to be achieved in their respective phases.
Solution Approach 2:
The system performs preliminary disengagement of sinkers from the knitted loops before the pickup operation. This preliminary action ensures that loops are properly positioned in the upper needle heads without sinker interference, enabling subsequent automated pickup by elements engaged below the upper latch.
3Manufacturing precision
If multiple cam types are used for actuating sinkers and needles, then precise control is achieved, but machine complexity and costs increase
Solution Approach 1:
The invention introduces a universal, multi-functional cam mechanism that performs multiple roles: it actuates the knockover sinkers during knitting, and can be shifted to a second position to disengage sinkers for pickup operations. This single cam replaces what would otherwise require multiple specialized cams, reducing machine complexity while maintaining precise control through its ability to perform different functions at different times.
Data Source
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AI summary
A method for preparing a tubular article, such as a sock or the like, for automated pickup at the end of its forming on a double cylinder circular machine with at least one feed or drop, and to a double cylinder circular machine for the execution thereof. The method in question is executed on a machine with at least one feed or drop (100) and with the needle cylinders (4, 5) actuatable with a rotary motion about their own axes (3) with respect to needle actuation cams, to cams (34) for actuating the knockover sinkers (33) and to the feed or drop (100). The method comprises: - a first step, which consists in transferring or retaining all the needles (8) in the lower needle cylinder (4) with the loops of the last row of knitting of the article (80), formed previously in the upper head (9a) of the needles (8), hooked, tensioning the article (80) downward inside the lower needle cylinder (4); - a second step, which consists in pushing upward the portion of the article (80) engaged with the needles (8); - a third step, which consists in moving all the needles (8) to the tuck stitch position; - a fourth step, which consists in progressively disengaging the knockover sinkers (33) from the article (80), moving the knockover sinkers (33) away from the axis (3) of the lower needle cylinder (4) at the feed or drop (100) owing to the rotation of the lower needle cylinder (4) about its own axis (3) with respect to the feed or drop (100) and to the needle actuation cams so that the article (80), owing to the upward thrust, moves so that the loops of its last row of knitting (80a) lie above the beak (33b) of the knockover sinkers (33) toward the upper head (9a) of the needles (8); - a fifth step, which consists in moving all the needles (8) to an intermediate position that is comprised between the tuck stitch position and the drop stitch position; - a sixth step, which consists in pushing the portion of the article (80) that is engaged with the needles (8) further upward; - a seventh step, which consists in lifting the needles (8) at least to the drop stitch position, keeping the article (80) pushed upward in order to retain the loops of the last row of knitting (80a) in the upper head (9a) of the needles (8).