Development of an Auto-Doffer for Covering Machines

Part 3 : Yarn Draw-in Device Installed on Vehicle

Abstract

Drawing-in process into hollow spindles on covering machines is so difficult and inefficient that its automation is especially hoped. The automatic drawing-in system, installed onto the vehicle individually driven wheels that runs around the factory floor, is developed in order to improve drawing-in operation. Results obtained are as follows :
(1) The auto-doffing system is composed of the automatic yarn draw-in apparatus, which can draw Spandex in both upper and lower hollow spindles simultaneously by air flow, and a vehicle which runs in contact with the covering machine.
(2) The developed device can draw-in 30D, 70D, 140D Spandex that are widely used and too fine to be easily drawn-in even by manual operation. Success rate more than 90% of Spandex drawing-in can be obtained by supplying the air pressure for the ejector at 0.5 MPa and for the injector at 0.4 MPa. It confirms that the developed device has practical utility.