Patent ID: 7568899

Claim:
An oscillating hauloff device for a blown film line, the device having a central axis, comprising: a first idler roll; a first turning bar; an idler roll pair; a second turning bar; a first gearing mechanism positioned along the central axis which maintains an angular position of the first turning bar midway between an angular position of the first idler roll and an angular position of the idler roll pair; and a second gearing mechanism positioned along the central axis which maintains an angular position of the second turning bar midway between an angular position of the idler roll pair and a fixed exit angle of a flattened film; the first idler roll, first turning bar, idler roll pair, and second turning bar rotatably moving about the central axis relative to one another; one roll of the idler roll pair maintaining an angular position across the central axis from the other roll of the idler roll pair as the idler roll pair rotates about the central axis; the flattened film passing between the rolls of the idler roll pair traveling through the central axis; and axes along the width of the flattened film being maintained substantially parallel to horizontal as the flattened film travels through the device.