摘要 |
<p>In a turret-type automatic winder, a method for automatically switching a yarn from a bobbin to an empty pirn when doffing the bobbin, in which a pirn holder, carrying the bobbin, is preliminarily accelerated by an acceleration disc to maintain the yarn tension within a proper range before yarn switching with a preset driving force of the acceleration disc onto the pirn holder increased continuously or progressively corresponding to the size of the bobbin. An apparatus for carrying out the above method comprises a pressure control device for a fluid operating a rotary actuator utilized for driving the acceleration disc onto the pirn holder, which device includes a cam displaceable with an increase in the bobbin size and a regulator valve actuated by the cam for outputting a regulated pressure to the rotary actuator.</p> |