Patent ID: 8627684

Claim:
A method for manufacturing a glass sheet, said method comprising the steps of: a) melting batch materials and forming the glass sheet; b) delivering the glass sheet to a pull roll apparatus; c) drawing the glass sheet and creating a cross-tension in the glass sheet using the pull roll apparatus which comprises: (i) a cantilevered vertically downtilted first stub roll pair for drawing a first edge portion of the glass sheet out away from a center of the glass sheet; (ii) a cantilevered vertically downtilted second stub roll pair for, at a location transversely opposite the first stub roll pair, drawing a second edge portion of the glass sheet out away from the center of the glass sheet, thereby creating a cross-tension in the glass sheet between the first stub roll pair and the second stub roll pair; (iii) a pull roll pair disposed below the first and second stub roll pairs for drawing the first edge portion and the opposing second edge portion of the glass sheet and creating a vertical draw tension on the glass sheet between the pull roll pair and the first and second stub roll pairs; d) monitoring the torque of at least one of the pull rolls in the pull roll pair; e) monitoring the torque of at least one of the stub rolls in the first stub roll pair and at least one of the stub rolls in the second stub roll pair; f) controlling the torque of at least one of the pull rolls in the pull roll pair; and g) controlling the torque of at least one of the stub rolls in the first stub roll pair and the torque of at least one of the stub rolls in the second stub roll pair to be a predetermined percentage of the torque of the at least one pull roll.