Abstract: A cylindrical ribbon engaging device is rotated about an axis of rotation substantially parallel to the direction of ribbon flow to positively exert lateral forces to an elongated substantial continuum of the marginal edge portion of the ribbon. Provisions are made to maximize lateral forces while minimizing longitudinal forces.

Abstract: A method of vertically positioning ribbon engaging devices in a glass forming chamber includes suspending a contact member within the chamber a known vertical distance relative to the device, moving the contact member toward the surface of a pool of molten metal contained within the glass forming chamber while moving the device to maintain the known vertical distance; and generating a signal when the contact member engages the pool of molten metal to indicate that the device is vertically positioned said known vertical distance from the surface of the pool of molten metal.

Abstract: A method of and apparatus for attenuating a ribbon of float glass in a temperature region below 1500.degree. F. (815.degree. C.) to diminish undesirable longitudinally oriented optical distortions. A cylindrical ribbon engaging device is rotated about an axis of rotation substantially parallel to the ribbon surface and the direction of ribbon flow to positively exert a plurality of outwardly directed lateral forces to an elongated substantial continuum of the marginal edge portion of the ribbon. Ribbon engaging elements are disposed about the circumferential surface of the cylindrical device in elongated helical paths, and the cylindrical device is rotated at an angular velocity such that the product of the angular velocity and the pitch of the helical paths equals the longitudinal velocity of the ribbon flow while the device acts upon the ribbon surface.

Abstract: A glass forming chamber for forming flat glass by a float method is provided with glass edge guide devices which extend through walls of the chamber and are externally supported. For each glass edge there is provided a device for positioning the glass edge guide to a desired position relative to the glass within the forming chamber and the walls of the forming chamber. The positioner comprises a drive support located adjacent the chamber with a drive device mounted on the support and a drive follower engaging a portion of the glass edge guide and engaging the drive to provide for positioning the glass edge guide responsive to the action of the drive.