High speed precision yarn winding system

In a high-speed precision winder for winding a running yarn onto a tube to form a cross wound yarn package, including spindle means for rotating the tube about a spindle axis, yarn traversing means for guiding running yarn received along an infeed path back and forth across a traverse zone adjacent said tube to form the cross wound package, and a bail roll disposed in rolling contact with the peripheral surface of the yarn package being wound;

• the improvement comprising a down pressure drive, a drive motor, and associated motor control circuit for said down pressure drive, said down pressure drive including down pressure adjusting means for continuously regulating the relative positions of said bail roll and said spindle axis with respect to each other, an upper main frame plate, a platform forming a support for said traversing means and bail roll, a pair of supporting arms fixed to pivot shaft members for arcuate movement about a horizontal pivot axis spaced above said plate and platform, a pair of upright bearing posts extending from said plate journalling said pivot shaft members for rotation, a reduction gearbox having a pair of opposite outputs coupled to said pivot shaft members for rotating the pivot shaft members and the supporting arms fixed thereto about said horizontal pivot axis from a lower start position upwardly through increasing angles to a raised doff position, said drive motor forming a retractor motor for driving the gearbox, bail roll supports carried by said platform for supporting said bail roll, a load cell forming the support structure for a portion of the platform beneath said bail roll for responding to variations in pressure thereon and producing load cell output signals, said load cell continuously sensing package down pressure on the bail roll and platform for producing said down pressure status signals and including means responsive thereto for generating activation and speed control signals for said retractor motor to vary the angular position of said support arms above said bail roll and traversing means on said platform for controlling the vertical position of the tube being driven by said spindle means.