1. Field of the Invention
This invention relates to the making of flat glass by delivering molten glass onto a pool of molten metal and supporting it thereon while cooling and forming the glass into a continuous sheet of flat glass. More particularly, this invention relates to conditioning molten glass just prior to delivery onto the molten metal for forming.
2. Description of the Prior Art
Molten glass may be delivered as a layer of molten glass onto molten metal and then formed into a continuous sheet or ribbon of glass according to the teachings of Heal, U.S. Pat. No. 710,357, or Hitchcock, U.S. Pat. No. 789,911. According to the teachings of Hitchcock and the later improvements of Edge and Kunkle disclosed in the application incorporated herein, it is useful to discharge the molten glass for forming from a pool of molten glass in a glassmaking furnace and deliver it along a substantially horizontal path onto the surface of the pool of molten metal. In one aspect the invention disclosed by Edge and Kunkle provides for cooling the molten glass beneath the surface of the pool of molten glass to establish an increased flow of molten glass at and near the surface of the pool of molten glass toward a discharge region of the pool of molten glass. This improves the quality of the formed glass sheet, particularly along its marginal edges where "herringbone" distortion is encountered in the methods disclosed by Hitchcock and Heal.
The present invention provides a method and apparatus for adapting the invention of Edge and Kunkle for improved performance when a forming chamber is connected to a glassmaking furnace in an unsymmetrical manner, particularly to allow the furnace to accommodate a plurality of forming chambers.