Piecing Arm Assembly Yarn Alignment Mechanism
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Solution Overview
Problem
Conventional automatic piecing devices in textile spinning mills often fail to properly catch and hold yarn ends during piecing, leading to inefficient and labor-intensive manual intervention due to frequent yarn breakages in ring spinning machines.
Innovation Solution
A piecing arm assembly with a pivotably connected arm, a roller, guide fingers, and a cutter unit, actuated by linear actuators, which positions the tail yarn to contact the delivery drafting roller at the nip point for effective piecing and snips excess yarn, improving the accuracy and efficiency of the piecing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If conventional automatic piecing devices are used, then yarn piecing automation is achieved, but the devices fail to properly catch and hold yarn ends during piecing
Solution Approach 1:
A tail yarn guide finger is introduced as an intermediary component between the tail yarn and the piecing mechanism. This guide finger actively guides and positions the tail yarn to ensure proper alignment and contact with the broken yarn end, thereby improving the reliability of yarn end catching and holding during automated piecing operations
Solution Approach 2:
The piecing mechanism is divided into distinct functional components including the tail yarn guide finger, roller, and cutter unit. Each component performs a specific function: the guide finger positions the tail yarn, the roller applies pressure to join the yarn ends, and the cutter trims excess. This segmentation allows each component to be optimized for its specific task, improving overall piecing reliability
2Reliability
If manual piecing is performed, then yarn breakage can be addressed, but continuous monitoring and manual piecing drain worker stamina and health
Solution Approach 1:
The automatic piecing device performs piecing operations autonomously without requiring continuous human intervention. The device detects yarn breakages, positions the tail yarn using the guide finger, joins the yarn ends with the roller, and trims excess with the cutter unit, thereby eliminating the need for workers to continuously monitor and manually piece broken yarns
Solution Approach 2:
The manual mechanical piecing action performed by workers is replaced with an automated mechanical system comprising the piecing arm assembly, guide finger, roller, and cutter unit. This substitution transfers the piecing task from human operators to an automated device, improving worker productivity and health while maintaining reliable yarn breakage handling
3Manufacturing precision
If piecing arm assembly positions tail yarn to contact delivery drafting roller at nip point, then piecing accuracy is improved, but device complexity increases
Solution Approach 1:
The piecing arm assembly is designed with movable and adjustable components that can dynamically position the tail yarn guide finger and roller to achieve precise contact at the nip point of the delivery drafting roller. The arm can move to different positions and angles to accommodate variations in yarn position and machine configuration, maintaining piecing accuracy while using a relatively simple mechanical structure
Data Source
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AI summary
A piecing arm assembly (15) for an automatic piecing apparatus (7), wherein the piecing arm assembly (15) comprises at least one arm (16) configured to displace between a first position and a second position. The at least one arm (16) has a plurality of guide fingers (19) and at least one roller (25) positioned on the plurality of guide fingers (19). A movable plate (18) with guide slot (20) is connected to a support member that extends from the at least one arm (16), said guide slot (20) is configured to displace linearly to align the tail yarn (12) for piecing.