Patent ID: 9556051
Date: 2017-01-31
CPC Classifications: C03B,G01B,G05B,G05D

Claim:
1. A method for controlling wedge variation in a glass ribbon comprising: flowing molten glass over converging sides of a forming vessel; drawing a glass ribbon from a root of the forming vessel, the glass ribbon having a width; measuring the wedge variation over at least a portion of the width of the glass ribbon for a time period of at least ten hours and generating a wedge variation signal based on said measuring; determining a high frequency component of the measured wedge variation and a low frequency component of the measured wedge variation by identifying peaks in a Fourier transform of the wedge variation signal wherein low frequency refers to periods greater than a first predetermined number of hours and high frequency refers to periods less than a second predetermined number of hours, wherein the second predetermined number of hours is less than the first predetermined number of hours, and a difference between the first and second predetermined number of hours is greater than or equal to two hours; determining a change in a tilt of the forming vessel based on the high frequency component of the measured wedge variation; determining a change in a temperature near a weir of the forming vessel based on the low frequency component of the measured wedge variation; and adjusting the tilt of the forming vessel based on the determined change in the tilt and adjusting the temperature near the weir of the forming vessel based on the determined change in the temperature near the weir to decrease the wedge variation over the width of the glass ribbon.