Glass manufacturing apparatus and methods

A method of manufacturing a glass ribbon comprising the steps of:

• forming a glass ribbon including a width;
• independently operating a first pull roll apparatus such that the first pull roll apparatus rotates with a substantially constant torque to draw the glass ribbon along a draw path extending transverse to the width of the glass ribbon;
• independently operating a second pull roll apparatus such that the second pull roll apparatus rotates with a substantially constant angular velocity to further draw the glass ribbon along the draw path;
• and
• adjusting the substantially constant torque of the first pull roll apparatus based on an operating condition of at least one of the first pull roll apparatus and the second pull roll apparatus.

A method of manufacturing a glass ribbon comprising the steps of:

• (I) forming a glass ribbon including a width;
• (II) independently operating a first pull roll apparatus such that the first pull roll apparatus rotates with a substantially constant torque to draw the glass ribbon along a draw path extending transverse to the width of the glass ribbon;
• (III) independently operating a second pull roll apparatus such that the second pull roll apparatus rotates with a substantially constant angular velocity to further draw the glass ribbon along the draw path;
• (IV) monitoring a force differential between the first pull roll apparatus and the second pull roll apparatus;
• (V) adjusting the substantially constant torque of the first pull roll apparatus to an adjusted torque in response to the force differential exceeding a predetermined range of force differentials;
• and
• (VI) continuing to independently operate the first pull roll apparatus such that the first pull roll apparatus rotates with a substantially constant adjusted torque while the force differential is within the predetermined range of force differentials.