Yarn core

Abstract

A yarn core has a start-up groove of V-shaped cross-section located near an outboard end of the core. A yarn latch is formed on the inboard wall of the groove for snagging the yarn. The yarn latch is located in a transition portion of the groove between a wider lead-in portion and a narrower clamping portion. The latch projects from the inboard wall generally in the direction of core rotation and extends partway across the width of the groove toward the outboard wall of the groove.

Description

FIELD OF THE INVENTION [0001] The invention relates to yarn cores on which yarn is wound during manufacture, and more particularly relates to yarn cores having a start-up groove for catching and clamping the yarn to start the winding process. BACKGROUND OF THE INVENTION [0002] Yarn cores are employed in the textile industry for winding and supporting yarn packages. In the package forming process, a moving yarn line is strung up onto a rapidly rotating empty core. In the manual string-up process, the moving yarn line is usually held by an aspirator gun and the yarn line brought into tangential contact with the rotating empty core. Typically, a start-up groove is provided in the surface of the core, normally adjacent to one end of the core. The yarn line is manually directed by movement of the aspirator gun into the groove, which grips the yarn line thereby initiating the wind-up process. Both co-current and counter-current string-up processes are used in the textile industry. In the ...

AI Technical Summary

Benefits of technology

The present invention provides a yarn core with a start-up groove that has a specially configured yarn latch for snagging the yarn so that it is less likely to skip back out of the groove, thereby improving the string-up efficiency of the core. The yarn cores have achieved string-up efficiencies of 99 percent or better. The yarn latch is located in the transition groove and is formed by a tapering protrusion projecting from the inboard wall of the groove. The lead-in and transition grooves have a shallow and steep sloping configuration, respectively, to facilitate the snagging of the yarn. The yarn start-up groove extends about half the circumference of the core and the lead-in groove has a constant width except for a tapered portion at the leading end. The clamping groove has a constant width along its length.

Problems solved by technology

However, it has been found that conventionally formed start-up grooves in textile yarn cores do not always reliably and repeatably perform these functions, particularly when used with different sized yarns, with yarns of different strengths, and / or with automated winding devices operating at high speeds.

When a string-up operation fails because the start-up groove fails to properly catch and grip the yarn, the failure represents a significant disruption to the winding process and substantial downtime can result.

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