Apparatus and method for controlling thickness of a flowing ribbon of molten glass

摘要

In the formation of sheet material from molten glass, a cooling tube is positioned in the forming area for directing a flow of cooling gas on discrete portions of the molten glass proximate a draw line or root to control local thickness variations in the sheet and thereby provide a uniform glass sheet thickness across the width of the sheet. The cooling tube is disposed in a pivot member configured to rotate about at least one axis, thereby causing an end of the cooling tube to direct the cooling gas over a wide range of angular positions across a portion of the width of the molten glass flowing over and from a forming body.